[SPIR-V] Add CodeGen test for the SPIR-V builtin lookup

Signed-off-by: Victor Lomuller <[email protected]>

Author: Naghasan

clang/test/CodeGenSPIRV/spirv-builtin-lookup.cpp

@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -fdeclare-spirv-builtins -fsyntax-only -emit-llvm %s -o - | FileCheck %s
+
+float acos(float val) {
+  // CHECK: @_Z4acosf
+  // CHECK: call float @_Z16__spirv_ocl_acosf
+  return __spirv_ocl_acos(val);
+}
+
+// CHECK: declare float @_Z16__spirv_ocl_acosf(float)
+
+double acos(double val) {
+  // CHECK: @_Z4acosd
+  // CHECK: call double @_Z16__spirv_ocl_acosd
+  return __spirv_ocl_acos(val);
+}
+
+// CHECK: declare double @_Z16__spirv_ocl_acosd(double)