Emit OpenCL metadata when targeting SPIR-V

This is required for converting function calls such as get_global_id()
into SPIR-V builtins.

Differential Revision: https://reviews.llvm.org/D123049

clang/lib/CodeGen/CodeGenModule.cpp

@@ -784,7 +784,7 @@ void CodeGenModule::Release() {
                               LangOpts.OpenMP);
 
   // Emit OpenCL specific module metadata: OpenCL/SPIR version.
-  if (LangOpts.OpenCL) {
+  if (LangOpts.OpenCL || (LangOpts.CUDAIsDevice && getTriple().isSPIRV())) {
     EmitOpenCLMetadata();
     // Emit SPIR version.
     if (getTriple().isSPIR()) {

clang/lib/Frontend/CompilerInvocation.cpp

@@ -3328,6 +3328,10 @@ void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
     // whereas respecting contract flag in backend.
     Opts.setDefaultFPContractMode(LangOptions::FPM_FastHonorPragmas);
   } else if (Opts.CUDA) {
+    if (T.isSPIRV()) {
+      // Emit OpenCL version metadata in LLVM IR when targeting SPIR-V.
+      Opts.OpenCLVersion = 200;
+    }
     // Allow fuse across statements disregarding pragmas.
     Opts.setDefaultFPContractMode(LangOptions::FPM_Fast);
   }

clang/test/CodeGenCUDASPIRV/kernel-cc.cu

@@ -7,3 +7,6 @@
 // CHECK: define spir_kernel void @_Z6kernelv()
 
 __attribute__((global)) void kernel() { return; }
+
+// CHECK: !opencl.ocl.version = !{[[OCL:![0-9]+]]}
+// CHECK: [[OCL]] = !{i32 2, i32 0}