Ensure that Vector<T> is tracked as "optimistic" for crossgen2

[tannergooding]

This resolves #87235

The issue was introduced in #85551 as the InstructionSet_VectorT### was included as part of the supportedInstructionSet and was therefore getting encoded as part of the required ISAs for a given image.

What this meant was that when we hit TryIncrementalLoad for System.Private.Corelib we'd try to apply the EagerFixups, find that the host machine supported InstructionSet_VectorT256 while the image said it required InstructionSet_VectorT128. This caused the entire image to be thrown away as invalid.

By instead tracking the Vector<T> size that's being targeted as the opportunistic set, we get the dependency flagged per method alongside any layout check required for Vector<T>. This allows just the method in question to be thrown away instead.

[tannergooding]

This brings the number of jitted methods for a Hello, World application (run from CORE_ROOT) back down to 64:

Assembly listing for method System.Runtime.CompilerServices.CastHelpers:StelemRef(System.Array,long,System.Object)
Assembly listing for method System.Runtime.CompilerServices.CastHelpers:LdelemaRef(System.Array,long,ulong):byref
Assembly listing for method System.SpanHelpers:IndexOfNullCharacter(ulong):int
Assembly listing for method System.SpanHelpers:NonPackedIndexOfValueType[short,System.SpanHelpers+DontNegate`1[short]](byref,short,int):int
Assembly listing for method System.ArgumentOutOfRangeException:ThrowIfNegative[int](int,System.String)
Assembly listing for method System.Text.Unicode.Utf16Utility:GetPointerToFirstInvalidChar(ulong,int,byref,byref):ulong
Assembly listing for method System.Text.Ascii:NarrowUtf16ToAscii(ulong,ulong,ulong):ulong
Assembly listing for method System.SpanHelpers:SequenceEqual(byref,byref,ulong):bool
Assembly listing for method System.Guid:TryFormatCore[ushort](System.Span`1[ushort],byref,int):bool:this
Assembly listing for method System.Diagnostics.Debug:Assert(bool)
Assembly listing for method System.Guid:FormatGuidVector128Utf8(System.Guid,bool):System.ValueTuple`3[System.Runtime.Intrinsics.Vector128`1[ubyte],System.Runtime.Intrinsics.Vector128`1[ubyte],System.Runtime.Intrinsics.Vector128`1[ubyte]]
Assembly listing for method System.HexConverter:AsciiToHexVector128(System.Runtime.Intrinsics.Vector128`1[ubyte],System.Runtime.Intrinsics.Vector128`1[ubyte]):System.ValueTuple`2[System.Runtime.Intrinsics.Vector128`1[ubyte],System.Runtime.Intrinsics.Vector128`1[ubyte]]
Assembly listing for method System.Runtime.Intrinsics.Vector128:ShuffleUnsafe(System.Runtime.Intrinsics.Vector128`1[ubyte],System.Runtime.Intrinsics.Vector128`1[ubyte]):System.Runtime.Intrinsics.Vector128`1[ubyte]
Assembly listing for method System.Number:UInt32ToDecChars[ushort](ulong,uint):ulong
Assembly listing for method System.SpanHelpers:IndexOfNullByte(ulong):int
Assembly listing for method System.RuntimeType+RuntimeTypeCache+MemberInfoCache`1[System.__Canon]:AddMethod(System.RuntimeType,long,int):System.Reflection.MethodBase:this
Assembly listing for method System.PackedSpanHelpers:IndexOf[System.SpanHelpers+DontNegate`1[short]](byref,short,int):int
Assembly listing for method System.PackedSpanHelpers:PackSources(System.Runtime.Intrinsics.Vector256`1[short],System.Runtime.Intrinsics.Vector256`1[short]):System.Runtime.Intrinsics.Vector256`1[ubyte]
Assembly listing for method System.PackedSpanHelpers:ComputeFirstIndexOverlapped(byref,byref,byref,System.Runtime.Intrinsics.Vector256`1[ubyte]):int
Assembly listing for method System.PackedSpanHelpers:FixUpPackedVector256Result(System.Runtime.Intrinsics.Vector256`1[ubyte]):System.Runtime.Intrinsics.Vector256`1[ubyte]
Assembly listing for method System.SpanHelpers:LastIndexOfValueType[short,System.SpanHelpers+DontNegate`1[short]](byref,short,int):int
Assembly listing for method System.Text.Ascii:WidenAsciiToUtf16(ulong,ulong,ulong):ulong
Assembly listing for method (dynamicClass):InvokeStub_EventAttribute.set_Level(System.Object,System.Object,ulong):System.Object
Assembly listing for method (dynamicClass):InvokeStub_EventAttribute.set_Message(System.Object,System.Object,ulong):System.Object
Assembly listing for method (dynamicClass):InvokeStub_EventAttribute.set_Task(System.Object,System.Object,ulong):System.Object
Assembly listing for method (dynamicClass):InvokeStub_EventAttribute.set_Opcode(System.Object,System.Object,ulong):System.Object
Assembly listing for method (dynamicClass):InvokeStub_EventAttribute.set_Version(System.Object,System.Object,ulong):System.Object
Assembly listing for method (dynamicClass):InvokeStub_EventAttribute.set_Keywords(System.Object,System.Object,ulong):System.Object
Assembly listing for method System.Number:Int64ToHexChars[ushort](ulong,ulong,int,int):ulong
Assembly listing for method System.SpanHelpers:IndexOfAnyInRangeUnsignedNumber[ushort,System.SpanHelpers+DontNegate`1[ushort]](byref,ushort,ushort,int):int
Assembly listing for method System.PackedSpanHelpers:IndexOfAnyInRange[System.SpanHelpers+DontNegate`1[short]](byref,short,short,int):int
Assembly listing for method System.SpanHelpers:SequenceCompareTo(byref,int,byref,int):int
Assembly listing for method Program:<Main>$(System.String[])
Assembly listing for method System.Console:WriteLine(System.String)
Assembly listing for method System.Console:get_Out():System.IO.TextWriter
Assembly listing for method System.Console:.cctor()
Assembly listing for method System.Console:<get_Out>g__EnsureInitialized|26_0():System.IO.TextWriter
Assembly listing for method System.ConsolePal:OpenStandardOutput():System.IO.Stream
Assembly listing for method System.Console:get_OutputEncoding():System.Text.Encoding
Assembly listing for method System.ConsolePal:get_OutputEncoding():System.Text.Encoding
Assembly listing for method System.Text.EncodingHelper:GetSupportedConsoleEncoding(int):System.Text.Encoding
Assembly listing for method System.Text.OSEncoding:.ctor(int):this
Assembly listing for method System.ConsolePal:GetStandardFile(int,int,bool):System.IO.Stream
Assembly listing for method System.ConsolePal:get_InvalidHandleValue():long
Assembly listing for method System.ConsolePal:ConsoleHandleIsWritable(long):bool
Assembly listing for method Interop+Kernel32:WriteFile(long,ulong,int,byref,long):int
Assembly listing for method System.ConsolePal+WindowsConsoleStream:.ctor(long,int,bool):this
Assembly listing for method System.IO.ConsoleStream:.ctor(int):this
Assembly listing for method Interop+Kernel32:GetFileType(long):uint
Assembly listing for method System.Console:CreateOutputWriter(System.IO.Stream):System.IO.TextWriter
Assembly listing for method System.Text.EncodingExtensions:RemovePreamble(System.Text.Encoding):System.Text.Encoding
Assembly listing for method System.IO.ConsoleStream:get_CanWrite():bool:this
Assembly listing for method System.ArgumentOutOfRangeException:ThrowIfNegativeOrZero[int](int,System.String)
Assembly listing for method System.Text.OSEncoding:GetEncoder():System.Text.Encoder:this
Assembly listing for method System.Text.OSEncoder:.ctor(System.Text.Encoding):this
Assembly listing for method System.Text.OSEncoder:Reset():this
Assembly listing for method System.IO.ConsoleStream:get_CanSeek():bool:this
Assembly listing for method System.Text.OSEncoding:GetMaxByteCount(int):int:this
Assembly listing for method System.Text.OSEncoder:GetBytes(ulong,int,ulong,int,bool):int:this
Assembly listing for method System.ConsolePal+WindowsConsoleStream:Flush():this
Assembly listing for method System.IO.ConsoleStream:Flush():this
Assembly listing for method System.Text.OSEncoding:WideCharToMultiByte(int,ulong,int,ulong,int):int
Assembly listing for method System.ConsolePal+WindowsConsoleStream:Write(System.ReadOnlySpan`1[ubyte]):this
Assembly listing for method System.ConsolePal+WindowsConsoleStream:WriteFileNative(long,System.ReadOnlySpan`1[ubyte],bool):int

[tannergooding]

An example of the r2rdump differences:

Before:

System.Numerics.Vector`1<ulong> System.Numerics.Vector.WidenUpper(System.Numerics.Vector`1<uint>)
Handle: 0x060029F1
Rid: 10737
EntryPointRuntimeFunctionId: 7433
Number of RuntimeFunctions: 1
Number of fixups: 2
    TableIndex 5, Offset 0ADF: System.Numerics.Vector`1<uint> Flags READYTORUN_LAYOUT_Alignment, READYTORUN_LAYOUT_Alignment_Native, READYTORUN_LAYOUT_GCLayout, READYTORUN_LAYOUT_GCLayout_Empty Size 16 (CHECK_TYPE_LAYOUT)
    TableIndex 5, Offset 0AE0: System.Numerics.Vector`1<ulong> Flags READYTORUN_LAYOUT_Alignment, READYTORUN_LAYOUT_Alignment_Native, READYTORUN_LAYOUT_GCLayout, READYTORUN_LAYOUT_GCLayout_Empty Size 16 (CHECK_TYPE_LAYOUT)

System.Numerics.Vector`1<ulong> System.Numerics.Vector.WidenUpper(System.Numerics.Vector`1<uint>)
Id: 7433
StartAddress: 0x002A1670
Size: 34 bytes
UnwindRVA: 0x0003CAF0
Version:            1
Flags:              0x03 EHANDLER UHANDLER
SizeOfProlog:       0x0004
CountOfUnwindCodes: 1
FrameRegister:      None
FrameOffset:        0x0
PersonalityRVA:     0x5D2F80
UnwindCode[0]: CodeOffset 0x0004 FrameOffset 0x0000 NextOffset 0x0 Op 24

Debug Info
    Bounds:
    Native Offset: 0x0, Prolog, Source Types: StackEmpty
    Native Offset: 0x4, IL Offset: 0x0019, Source Types: StackEmpty
    Native Offset: 0x13, IL Offset: 0x0034, Source Types: StackEmpty
    Native Offset: 0x1D, Epilog, Source Types: StackEmpty

    Variable Locations:
    Variable Number: 4294967294
    Start Offset: 0x0
    End Offset: 0x1A
    Loc Type: VLT_REG
    Register: RCX

    Variable Number: 0
    Start Offset: 0x0
    End Offset: 0xB
    Loc Type: VLT_REG
    Register: RDX

After:

System.Numerics.Vector`1<ulong> System.Numerics.Vector.WidenUpper(System.Numerics.Vector`1<uint>)
Handle: 0x060029F1
Rid: 10737
EntryPointRuntimeFunctionId: 7433
Number of RuntimeFunctions: 1
Number of fixups: 3
    TableIndex 5, Offset 0020: CHECK_InstructionSetSupport X86Base+ Sse+ Sse2+ VectorT128+
    TableIndex 5, Offset 0AE0: System.Numerics.Vector`1<uint> Flags READYTORUN_LAYOUT_Alignment, READYTORUN_LAYOUT_Alignment_Native, READYTORUN_LAYOUT_GCLayout, READYTORUN_LAYOUT_GCLayout_Empty Size 16 (CHECK_TYPE_LAYOUT)
    TableIndex 5, Offset 0AE1: System.Numerics.Vector`1<ulong> Flags READYTORUN_LAYOUT_Alignment, READYTORUN_LAYOUT_Alignment_Native, READYTORUN_LAYOUT_GCLayout, READYTORUN_LAYOUT_GCLayout_Empty Size 16 (CHECK_TYPE_LAYOUT)

System.Numerics.Vector`1<ulong> System.Numerics.Vector.WidenUpper(System.Numerics.Vector`1<uint>)
Id: 7433
StartAddress: 0x002A1790
Size: 34 bytes
UnwindRVA: 0x0003CB18
Version:            1
Flags:              0x03 EHANDLER UHANDLER
SizeOfProlog:       0x0004
CountOfUnwindCodes: 1
FrameRegister:      None
FrameOffset:        0x0
PersonalityRVA:     0x5D30A0
UnwindCode[0]: CodeOffset 0x0004 FrameOffset 0x0000 NextOffset 0x0 Op 24

Debug Info
    Bounds:
    Native Offset: 0x0, Prolog, Source Types: StackEmpty
    Native Offset: 0x4, IL Offset: 0x0019, Source Types: StackEmpty
    Native Offset: 0x13, IL Offset: 0x0034, Source Types: StackEmpty
    Native Offset: 0x1D, Epilog, Source Types: StackEmpty

    Variable Locations:
    Variable Number: 4294967294
    Start Offset: 0x0
    End Offset: 0x1A
    Loc Type: VLT_REG
    Register: RCX

    Variable Number: 0
    Start Offset: 0x0
    End Offset: 0xB
    Loc Type: VLT_REG
    Register: RDX

[tannergooding]

Note that before #85551 the number of jitted methods for Hello, World was 62, the two new methods are:

• System.SpanHelpers:SequenceEqual(byref,byref,ulong):bool
• System.SpanHelpers:SequenceCompareTo(byref,int,byref,int):int

These two methods are no longer being used for AOT because they do in fact use Vector<T> along some code path and that causes it to be flagged as VectorT128+.

These code paths are only being kept around for Mono currently and so it may be desirable to #ifdef them out for CoreCLR as the simple fix.

[stephentoub]

These two methods are no longer being used for AOT because they do in fact use Vector along some code path and that causes it to be flagged as VectorT128+. These code paths are only being kept around for Mono currently and so it may be desirable to #ifdef them out for CoreCLR as the simple fix.

#85916 has been pending to delete those fallbacks entirely. To move things along, I could update it to instead ifdef them to just be for mono.