Fix MethodBase.GetCurrentMethod with runtime async (#122710)

Fixes #122546.

---------

Co-authored-by: Eduardo Velarde <evelardepola@microsoft.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: 3 people

src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/Compilation.cs

@@ -204,6 +204,11 @@ public MethodDesc ExpandIntrinsicForCallsite(MethodDesc intrinsicMethod, MethodD
             {
                 if (intrinsicMethod.Signature.IsStatic && intrinsicMethod.Name.SequenceEqual("GetCurrentMethod"u8))
                 {
+                    if (callsiteMethod.IsAsyncVariant())
+                    {
+                        // For async methods, we need to get the MethodBase for the thunk variant.
+                        callsiteMethod = TypeSystemContext.GetTargetOfAsyncVariantMethod(callsiteMethod);
+                    }
                     return _methodBaseGetCurrentMethodThunks.GetHelper(callsiteMethod).InstantiateAsOpen();
                 }
             }

src/tests/async/reflection/reflection.cs

@@ -247,7 +247,6 @@ public static void UnsafeAccessors()
     }
 
     [Fact]
-    [ActiveIssue("https://github.com/dotnet/runtime/issues/122517", typeof(TestLibrary.Utilities), nameof(TestLibrary.Utilities.IsNativeAot))]
     public static void CurrentMethod()
     {
         // Note: async1 leaks implementation details here and returns "Void MoveNext()"