Manifest DllImportSourceGenerator as a generator (#62836)

src/libraries/System.Runtime.InteropServices/gen/Directory.Build.props

@@ -8,5 +8,6 @@
     <EnableDefaultItems>true</EnableDefaultItems>
     <CLSCompliant>false</CLSCompliant>
     <ILLinkTrimAssembly>false</ILLinkTrimAssembly>
+    <IsGeneratorProject>true</IsGeneratorProject>
   </PropertyGroup>
 </Project>
\ No newline at end of file

src/tests/Common/Directory.Build.targets

@@ -176,12 +176,7 @@
       <AotCompilerCopyLocal Include="$(CoreCLRArtifactsPath)aotsdk/**/*" TargetDir="nativeaot/sdk/" />
       <AotCompilerCopyLocal Include="$(CoreCLRArtifactsPath)build/**/*" TargetDir="nativeaot/build/" />
       <AotCompilerCopyLocal Include="$(TargetingPackPath)/*" TargetDir="nativeaot/framework/" />
-
-      <!-- Works around https://github.com/dotnet/runtime/issues/62372 -->
-      <_FixedRuntimeCopyLocalItems Include="@(RuntimeCopyLocalItems)" />
-      <_FixedRuntimeCopyLocalItems Remove="@(_FixedRuntimeCopyLocalItems)" Condition="'%(Filename)' == 'Microsoft.Interop.DllImportGenerator'" />
-
-      <AotCompilerCopyLocal Include="@(_FixedRuntimeCopyLocalItems)" TargetDir="nativeaot/framework/" />
+      <AotCompilerCopyLocal Include="@(RuntimeCopyLocalItems)" TargetDir="nativeaot/framework/" />
     </ItemGroup>
 
     <ItemGroup Condition="'$(RuntimeFlavor)' == 'mono' and '$(IsDesktopOS)' == 'true' " >

src/tests/build.proj

@@ -122,10 +122,7 @@
     </RemoveDuplicates>
     <ItemGroup>
       <TestsAndAssociatedAssemblies Include="%(TestDirs.Identity)/*.dll" />
-      <CoreRootDlls Include="$(CORE_ROOT)/*.dll"
-        Exclude="$(CORE_ROOT)/xunit.performance.api.dll;
-                 $(CORE_ROOT)/Microsoft.Interop.DllImportGenerator.dll;
-                 $(CORE_ROOT)/Microsoft.Interop.SourceGeneration.dll" />
+      <CoreRootDlls Include="$(CORE_ROOT)/*.dll" Exclude="$(CORE_ROOT)/xunit.performance.api.dll" />
       <AllDlls Condition="'$(MonoFullAot)' == 'true'" Include="@(TestsAndAssociatedAssemblies);@(CoreRootDlls)" />
       <AllDlls Condition="'$(MonoFullAot)' != 'true'" Include="@(TestsAndAssociatedAssemblies)" />
     </ItemGroup>