Dotnet build fails for Windows arm64

[kunalspathak]

Version Used:
Microsoft (R) Visual C# Compiler version 3.6.0-2.20153.4 (6f2112b)

** Platform **
Windows ARM64 netcoreapp5.0

Steps to Reproduce:

1. dotnet new console
2. dotnet build created_project.csproj

Expected Behavior:
Project builds

Actual Behavior:

CSC : error CS0041: Unexpected error writing debug information -- 'An attempt was made to load a program with an incorrect format. (0x8007000B)

The reason being that CSC tries to load amd64 version of Microsoft.DiaSymReader.Native.amd64.dll to write symbols.

@jaredpar suggested to use /debug:pdbonly which makes it works, but I am trying to run BenchmarkDotNet which builds project on fly and it doesn't pass that flag to individual benchmark project causing it to fail with the above error.

[kunalspathak]

//cc @tmat

[tmat]

Blocked on https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1034547

[adamsitnik]

@tmat The blocking issue has been solved a year ago. What would it take to fix it in Roslyn now?

[adamsitnik]

Update: I've found the places in the code that would need to be updated:

https://github.com/dotnet/roslyn/blob/main/eng/targets/DiaSymReaderNative.targets
https://github.com/dotnet/roslyn/blob/main/src/Compilers/Core/Portable/DiaSymReader/SymUnmanagedFactory.cs

roslyn/src/NuGet/Microsoft.Net.Compilers.Toolset/DesktopCompilerArtifacts.targets

Lines 32 to 33 in c8ebc86

	<DesktopCompilerArtifact Include="$(ArtifactsBinDir)csc\$(Configuration)\net472\Microsoft.DiaSymReader.Native.amd64.dll" Condition="'$(DotNetBuildFromSource)' != 'true'"/>
	<DesktopCompilerArtifact Include="$(ArtifactsBinDir)csc\$(Configuration)\net472\Microsoft.DiaSymReader.Native.x86.dll" Condition="'$(DotNetBuildFromSource)' != 'true'"/>

But it seems that there are no arm CI legs to verify such changes as of now: #59421 (comment)

[tmat]

Duplicate of #59421