generic math: Don't include System.Runtime reference assembly when pu…

…blishing (#57071)

System.Runtime.Experimental.csproj builds a reference assembly called System.Runtime.dll that should be used when compiling, but should not be included when packaging. For normal out of tree projects this happens because the System.Runtime.Experimental.nupkg makes it evident that <PackageReference Include="System.RuntimeExperimental" /> only provides reference assembly assets. But in-tree for <ProjectReference> we have to be explicit.

Fixes #55823
Fixes #55767
Fixes #56836

src/libraries/System.Runtime.Experimental/tests/System.Runtime.Experimental.Tests.csproj

@@ -41,7 +41,8 @@
     <Compile Include="$(LibrariesProjectRoot)System.Runtime\tests\System\UIntPtrTests.GenericMath.cs" />
   </ItemGroup>
   <ItemGroup>
-    <ProjectReference Include="$(LibrariesProjectRoot)System.Runtime.Experimental\ref\System.Runtime.Experimental.csproj" />
+    <!-- it's a reference assembly, but the project system doesn't know that - include it during compilation, but don't publish it -->
+    <ProjectReference Include="$(LibrariesProjectRoot)System.Runtime.Experimental\ref\System.Runtime.Experimental.csproj" IncludeAssets="compile" Private="false" />
     <ProjectReference Include="$(CommonTestPath)TestUtilities.Unicode\TestUtilities.Unicode.csproj" />
   </ItemGroup>
 </Project>

src/libraries/tests.proj

@@ -52,9 +52,6 @@
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Security.Cryptography.Csp\tests\System.Security.Cryptography.Csp.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Threading.Thread\tests\System.Threading.Thread.Tests.csproj" />
 
-    <!-- Crash https://github.com/dotnet/runtime/issues/55823 -->
-    <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Runtime.Experimental\tests\System.Runtime.Experimental.Tests.csproj" />
-
     <!-- Actual test failures -->
     <!-- https://github.com/dotnet/runtime/issues/37088 -->
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Runtime\tests\System.Runtime.Tests.csproj" />
@@ -156,9 +153,6 @@
     <!-- https://github.com/dotnet/runtime/issues/52120 -->
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Net.Security/tests/FunctionalTests/System.Net.Security.Tests.csproj" />
 
-    <!-- Crash https://github.com/dotnet/runtime/issues/55823 -->
-    <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Runtime.Experimental\tests\System.Runtime.Experimental.Tests.csproj" />
-
     <!-- Crashes on CI but passes locally https://github.com/dotnet/runtime/issues/52615 -->
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)Microsoft.Extensions.Http/tests/Microsoft.Extensions.Http.Tests/Microsoft.Extensions.Http.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)Microsoft.Extensions.Logging/tests/Common/Microsoft.Extensions.Logging.Tests.csproj" />
@@ -236,9 +230,6 @@
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Security.Cryptography.Primitives\tests\System.Security.Cryptography.Primitives.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Security.Cryptography.Xml\tests\System.Security.Cryptography.Xml.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Security.Cryptography.X509Certificates\tests\System.Security.Cryptography.X509Certificates.Tests.csproj" />
-
-    <!-- Issue: https://github.com/dotnet/runtime/issues/55767 -->
-    <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Runtime.Experimental\tests\System.Runtime.Experimental.Tests.csproj" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetOS)' == 'Browser' and '$(BuildAOTTestsOnHelix)' == 'true' and '$(RunDisabledWasmTests)' != 'true'">