CsWin32 should avoid Unsafe.SkipInit when it doesn't exist in the compilation

[AArnott]

Discussed in #1191

^{Originally posted by thxkiwi May 31, 2024}
I have a project that I wrote using targeting framework net80 and trying to get it working with net481/LangVersion 10.

CsWin32: 0.3.106
Using Visual Studio 17.10.0.

I've modified the SDK project files to be

  <PropertyGroup>
    <TargetFramework>net481</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
    <Platforms>x64</Platforms>
	  <LangVersion>10</LangVersion>
	  <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
  </PropertyGroup>

CsWin32 is generating Windows.Win32.char.InlineArrays.g.cs:84 - Unsafe.SkipInit(out __char_260 result);

		public static unsafe implicit operator __char_260(ReadOnlySpan<char> value)
		{
			Unsafe.SkipInit(out __char_260 result);
			Span<char> target = new Span<char>(result.Value, SpanLength);
			value.CopyTo(target);
			int initLength = value.Length;
			target.Slice(initLength, SpanLength - initLength).Clear();
			return result;
		}

That seems to be .NET 8 only still.

Am I missing something (including "the point") here? It seemed possible and reasonable to target net481 and LangVersion 10.

Help and guidance greatly appreciated.

[AArnott]

Per the discussion this came from, the issue seems to be that Unsafe.SkipInit comes from a package that wasn't referenced in the compilation. CsWin32 should be more cautious about this.