[OpenCL] Expose wg collective functions for CL3 SPIR targets

Since the SPIR/SPIR-V targets enable all known features, we must
ensure the Work-group Collective Functions feature macro is set for
OpenCL 3.0.

Fixes #55770

Author: svenvh

clang/lib/Headers/opencl-c-base.h

@@ -68,6 +68,7 @@
 #if (__OPENCL_CPP_VERSION__ == 202100 || __OPENCL_C_VERSION__ == 300)
 // For the SPIR and SPIR-V target all features are supported.
 #if defined(__SPIR__) || defined(__SPIRV__)
+#define __opencl_c_work_group_collective_functions 1
 #define __opencl_c_atomic_order_seq_cst 1
 #define __opencl_c_atomic_scope_device 1
 #define __opencl_c_atomic_scope_all_devices 1