[clang] [OpenCL] Set KHR extensions minimum version to OpenCL 1.0 (PR #175120)

[Sven van Haastregt via cfe-commits]

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@@ -17,6 +17,13 @@
 #endif //cl_khr_depth_images
 #endif //defined(__opencl_c_images)
 
+#if defined(cl_khr_depth_images) || defined(__OPENCL_CPP_VERSION__) ||         \
+    (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+// Internal feature macro to provide depth image builtins.
+#define __opencl_depth_image_builtins 1
+#endif // defined(cl_khr_depth_images) || defined(__OPENCL_CPP_VERSION__) ||
+       // (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+
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svenvh wrote:

I wonder if we should move this to `clang/lib/Headers/opencl-c-base.h` and whether any guards in `clang/lib/Sema/OpenCLBuiltins.td` will need updating?  To avoid `opencl-c.h` and `OpenCLBuiltins.td` going out of sync.

https://github.com/llvm/llvm-project/pull/175120