[clang] [clang][SYCL] Add SYCL spelling for AS attributes (PR #200849)

[Tom Honermann via cfe-commits]

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@@ -26,14 +26,16 @@
 #define __SPIRV_convergent __attribute__((convergent))
 #define __SPIRV_inline __attribute__((always_inline))
 
-#define __global __attribute__((opencl_global))
-#define __local __attribute__((opencl_local))
-#define __private __attribute__((opencl_private))
-#define __constant __attribute__((opencl_constant))
 #ifdef __SYCL_DEVICE_ONLY__
-#define __generic
+#define __GLOBALAS [[clang::sycl_global]]
+#define __LOCALAS [[clang::sycl_local]]
+#define __PRIVATEAS [[clang::sycl_private]]
+#define __GENERICAS [[clang::sycl_generic]]
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tahonermann wrote:

The other macros that are defined and undefined in this header file use a `__SPIRV_` prefix; I think these should too.
```suggestion
#define __SPIRV_GLOBALAS [[clang::sycl_global]]
#define __SPIRV_LOCALAS [[clang::sycl_local]]
#define __SPIRV_PRIVATEAS [[clang::sycl_private]]
#define __SPIRV_GENERICAS [[clang::sycl_generic]]
```

https://github.com/llvm/llvm-project/pull/200849