Some hardware intrinsic ILLInk.Substitution entries may be unnecessary

[tannergooding]

As per #83040 (comment), some of the ILLink.Substitution entries may be unnecessary since corelib already compiles in a different copy of the ISAs (*.PlatformNotSupported.cs) which return constant false.

We should double check that removing these are ok and make the files shorter if possible.

-- Noting the Vector64/128/256/512 entries are needed since they do not return constant false and are instead recursive by default.

[dotnet-issue-labeler]

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[jkotas]

copy of the ISAs (*.PlatformNotSupported.cs) which return constant false.

These methods are marked with [Intrinsic] attribute. I believe that it is make AltJit work, among other things.

Linker does not look at bodies of methods marked `[Intrinsic]. The IL of these methods often does not match what the method actually does. The substitution is required to tell the linker what the method actually does.

[ghost]

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Issue Details

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As per #83040 (comment), some of the ILLink.Substitution entries may be unnecessary since corelib already compiles in a different copy of the ISAs (*.PlatformNotSupported.cs) which return constant false.

We should double check that removing these are ok and make the files shorter if possible.

-- Noting the Vector64/128/256/512 entries are needed since they do not return constant false and are instead recursive by default.

Author:	tannergooding
Assignees:	-
Labels:	untriaged, area-Tools-ILLink
Milestone:	-

[tannergooding]

Thanks for the info! Will close this as unnecessary then.