Emit compiler version to Windows PDB

[tmat]

Uses new SymReader API to write compiler version info to Windows PDB.
No op if the SymReader does not implement the API.

The new API will be added to Microsoft.DiaSymReader.Native.*.dll (not available yet). On .NET Core the library is loaded from the CLR runtime so this will require the runtime to be updated first before we can test on Core.

Similar change in Crossgen: dotnet/runtime#59686

The compiler emits the following Windows PDB S_COMPILE3 record:

** Module: "* CompilerInfo *" from "86F52079"


(000004) S_COMPILE3:
         Language: MSIL
         Target processor: Pentium III
         Compiled for edit and continue: no
         Compiled without debugging info: no
         Compiled with LTCG: no
         Compiled with /bzalign: no
         Managed code present: no
         Compiled with /GS: no
         Compiled with /hotpatch: no
         Converted by CVTCIL: no
         MSIL module: no
         Compiled with /sdl: no
         Compiled with pgo: no
         .EXP module: no
         Pad bits = 0x0000
         Frontend Version: Major = 0, Minor = 0, Build = 0, QFE = 0
         Backend Version: Major = 42, Minor = 42, Build = 42, QFE = 42424
         Version string: C# - 4.0.0-dev

[tmat]

@jaredpar

[jcouv]

Probably needs some test

[tmat]

Probably needs some test

Definitely, but can't really test until Microsoft.DiaSymReader.Native.*.dll is available.

[jcouv]

When will it be available?

[davidwrighton]

@tmat did you intend to say on .NET Framework it depends on the globally installed version, or is it really the case that the .NET Core version depends on the full framework copy of diasymreader?

[tmat]

@tmat did you intend to say on .NET Framework it depends on the globally installed version, or is it really the case that the .NET Core version depends on the full framework copy of diasymreader?

No, nothing depends on globally installed version.
We ship it with the compiler, but on .NET Core the runtime also ships it and it's loaded from there.

[jcouv]

LGTM Thanks (iteration 5). From discussion with Jared I understand this is time sensitive and was tested manually. Please open a follow-up issue to add tests once the package is available.

[jcouv]

Don't forget to retarget this PR to the 17.0 branch as needed.