[clang] [AMDGPU] Support the OpenCL generic addrspace feature by default (PR #137636)

[Fraser Cormack via cfe-commits]

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@@ -146,3 +146,8 @@
 #pragma OPENCL EXTENSION cl_khr_subgroups: enable
 // expected-warning at -1{{unsupported OpenCL extension 'cl_khr_subgroups' - ignoring}}
 
+#ifdef __opencl_c_generic_address_space
+#error "Incorrect __opencl_c_generic_address_space define"
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frasercrmck wrote:

Yeah I do too, but I was trying to go with the style of the other checks in this test. Or is it particularly this generic address space one, and the others are okay?

https://github.com/llvm/llvm-project/pull/137636