[llvm] [TableGen] Emit OpName as an enum class instead of a namespace (PR #125313)

[Jay Foad via llvm-commits]

================
@@ -17,6 +17,7 @@
 #ifndef LLVM_LIB_TARGET_AMDGPU_MCA_AMDGPUCUSTOMBEHAVIOUR_H
 #define LLVM_LIB_TARGET_AMDGPU_MCA_AMDGPUCUSTOMBEHAVIOUR_H
 
+#include "Utils/AMDGPUBaseInfo.h"
----------------
jayfoad wrote:

I don't quite understand why this is required now but was not required before.

https://github.com/llvm/llvm-project/pull/125313