cleanup duplicate property implementation

[kasperk81]

may or may not fix dotnet/installer#19667 (comment) and may or may not unblock the next one dotnet/installer#19669

@ViktorHofer @MichaelSimons @rainersigwald

[ViktorHofer]

If the linker trims the msbuild assemblies either here or in the SDK layout, then I could see how this change would solve the TypeLoadException. Given that this is a positive change anyways, I would take it.

[ViktorHofer]

@dotnet/kitten can you please approve and merge this PR in? We need a new SDK build with this change the sooner the better.

[ladipro]

If the linker trims the msbuild assemblies either here or in the SDK layout

Are SDK assemblies really trimmed? I am skeptical this change would help but it won't hurt either. In any case, it would be good to understand the root cause.

[rainersigwald]

Are SDK assemblies really trimmed?

They are not.

[kasperk81]

it did help. the next error in source-build test build fixed in #10111

[rainersigwald]

@kasperk81 this change did not help. Per @ViktorHofer the problem with the source-build in installer is a build-vs-runtime split across dotnet/runtime@b8fe1d0, which will be addressed by dotnet/installer#19684.

[kasperk81]

@rainersigwald, previous error was:

System.TypeLoadException: Method 'get_Count' in type 'Microsoft.Build.Collections.PropertyDictionary`1' from assembly 'Microsoft.Build, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' does not have an implementation.

next error is:

System.TypeLoadException: Method 'ContainsKey' in type 'Microsoft.Build.Collections.PropertyDictionary`1' from assembly 'Microsoft.Build, Version=15.1.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' does not have an implementation.

so get_Count is fixed by this pr, and #10111 will fix ContainsKey.

[rainersigwald]

I should rephrase: this change did not resolve the underlying problem, which was with compiling and running across an incompatible boundary in the .NET runtime.

[kasperk81]

i can see that runtime change has subtle effects in multiple places and people are pleading to bring it back dotnet/runtime#31001 (comment).

[rainersigwald]

Yeah, and that should be fine--it's not a breaking change (except for C++/CLI, I guess). The problem arose when we compiled targeting .NET-9-with-that-change (which I guess changed some overload resolution) and then ran on .NET-9-without-that-change. That shouldn't happen again even if it comes back (unless it's then backed out again).