[clang] [llvm] [SPIRV] Use AMDGPU ABI for AMDGCN flavoured SPIRV (PR #169865)

[Matt Arsenault via cfe-commits]

================
@@ -9,6 +9,11 @@
 #include "ABIInfoImpl.h"
 #include "HLSLBufferLayoutBuilder.h"
 #include "TargetInfo.h"
+#include "clang/Basic/LangOptions.h"
+#include "llvm/IR/DerivedTypes.h"
+
+#include <stdint.h>
----------------
arsenm wrote:

```suggestion
#include <cstdint>
```

But I'd be surprised you need this? 

https://github.com/llvm/llvm-project/pull/169865