[clang] [clang][SYCL] Implement address space attributes for SYCL (PR #200849)

[via cfe-commits]

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@@ -13537,6 +13537,9 @@ def err_sycl_special_type_num_init_method : Error<
   "method defined">;
 def err_sycl_device_invalid_target : Error<
   "%0 is not a supported SYCL device target">;
+def err_sycl_address_space_qualified_object : Error<
+  "'%0' attribute may only be applied to the object type of an object pointer "
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elizabethandrews wrote:

I added a couple of additional function pointer tests. I did not change the diagnostic yet. 

`%0' attribute cannot appear in the top-level type of a variable declaration` reads a bit odd to me but I am not opposed to it. 

I also considered `"'%0' attribute may only be applied to the pointee of a pointer or the referent of a reference"` . This however does not accurately catch the function pointer case but I don't know if that matters since the generic diagnostic fires for it. 

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