Gracefully end codegen when reflect used in a non-Vulkan env

Author: Icohedron

llvm/lib/Target/SPIRV/SPIRVInstructionSelector.cpp

@@ -3030,8 +3030,10 @@ bool SPIRVInstructionSelector::selectIntrinsic(Register ResVReg,
     return selectExtInst(ResVReg, ResType, I, CL::fract, GL::Fract);
   case Intrinsic::spv_normalize:
     return selectExtInst(ResVReg, ResType, I, CL::normalize, GL::Normalize);
-  case Intrinsic::spv_reflect: // There is no CL equivalent of Reflect
-    return selectExtInst(ResVReg, ResType, I, GL::Reflect);
+  case Intrinsic::spv_reflect:
+    if (STI.isVulkanEnv()) // There is no CL equivalent of Reflect
+      return selectExtInst(ResVReg, ResType, I, GL::Reflect);
+    break;
   case Intrinsic::spv_rsqrt:
     return selectExtInst(ResVReg, ResType, I, CL::rsqrt, GL::InverseSqrt);
   case Intrinsic::spv_sign: