Add missing type forward for CompilerServices.Closure (#119197)

* Initial plan

* Add missing type forwards for CompilerServices.Closure, CallSiteOps, and RuntimeOps

Co-authored-by: ericstj <[email protected]>

* Fix reference source

* Remove obsolete CallSiteOps and RuntimeOps types per feedback

Co-authored-by: ericstj <[email protected]>

* Apply suggestions from code review

Remove empty lines added by copilot

Co-authored-by: Fred Silberberg <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: ericstj <[email protected]>
Co-authored-by: Eric St. John <[email protected]>
Co-authored-by: Fred Silberberg <[email protected]>

Author: 3 people

src/libraries/System.Linq.Expressions/ref/System.Linq.Expressions.cs

@@ -1215,6 +1215,13 @@ internal CallSite() { }
         [System.Diagnostics.CodeAnalysis.RequiresDynamicCodeAttribute("Creating arrays at runtime requires dynamic code generation.")]
         public static System.Runtime.CompilerServices.CallSite<T> Create(System.Runtime.CompilerServices.CallSiteBinder binder) { throw null; }
     }
+    [System.ComponentModel.EditorBrowsableAttribute(System.ComponentModel.EditorBrowsableState.Never)]
+    public sealed partial class Closure
+    {
+        public readonly object[] Constants;
+        public readonly object[]? Locals;
+        public Closure(object[] constants, object[]? locals) { }
+    }
     public abstract partial class DebugInfoGenerator
     {
         protected DebugInfoGenerator() { }

src/libraries/System.Linq.Expressions/src/CompatibilitySuppressions.xml

@@ -9,10 +9,6 @@
     <DiagnosticId>CP0001</DiagnosticId>
     <Target>T:System.Runtime.CompilerServices.CallSiteOps</Target>
   </Suppression>
-  <Suppression>
-    <DiagnosticId>CP0001</DiagnosticId>
-    <Target>T:System.Runtime.CompilerServices.Closure</Target>
-  </Suppression>
   <Suppression>
     <DiagnosticId>CP0001</DiagnosticId>
     <Target>T:System.Runtime.CompilerServices.RuntimeOps</Target>

src/libraries/shims/System.Core/src/System.Core.cs

@@ -184,6 +184,7 @@
 [assembly: System.Runtime.CompilerServices.TypeForwardedTo(typeof(System.Runtime.CompilerServices.CallSite<>))]
 [assembly: System.Runtime.CompilerServices.TypeForwardedTo(typeof(System.Runtime.CompilerServices.CallSiteBinder))]
 [assembly: System.Runtime.CompilerServices.TypeForwardedTo(typeof(System.Runtime.CompilerServices.CallSiteHelpers))]
+[assembly: System.Runtime.CompilerServices.TypeForwardedTo(typeof(System.Runtime.CompilerServices.Closure))]
 [assembly: System.Runtime.CompilerServices.TypeForwardedTo(typeof(System.Runtime.CompilerServices.DebugInfoGenerator))]
 [assembly: System.Runtime.CompilerServices.TypeForwardedTo(typeof(System.Runtime.CompilerServices.DynamicAttribute))]
 [assembly: System.Runtime.CompilerServices.TypeForwardedTo(typeof(System.Runtime.CompilerServices.ExtensionAttribute))]