[libclc] [libclc] Use CLC atomic functions for legacy OpenCL atom/atomic builtins (PR #168325)

[Matt Arsenault via cfe-commits]

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@@ -6,32 +6,35 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include <clc/atomic/clc_atomic_fetch_add.h>
 #include <clc/opencl/atomic/atom_add.h>
-#include <clc/opencl/atomic/atomic_add.h>
+
+// Non-volatile overloads are for backward compatibility with OpenCL 1.0.
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arsenm wrote:

I don't remember the history here, but isn't this backwards? Even if the language is volatile qualified we probably shouldn't be emitting IR with volatile markers 

https://github.com/llvm/llvm-project/pull/168325