[AMDGPU] Added a new metadata for multi grid sync implicit argument

Patch by Christudasan Devadasan.

Differential Revision: https://reviews.llvm.org/D63886


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365217 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Support/AMDGPUMetadata.cpp

@@ -65,6 +65,8 @@ struct ScalarEnumerationTraits<ValueKind> {
     YIO.enumCase(EN, "HiddenDefaultQueue", ValueKind::HiddenDefaultQueue);
     YIO.enumCase(EN, "HiddenCompletionAction",
                  ValueKind::HiddenCompletionAction);
+    YIO.enumCase(EN, "HiddenMultiGridSyncArg",
+		 ValueKind::HiddenMultiGridSyncArg);
   }
 };