[gn build] Port 353b5e4

Author: llvmgnsyncbot

llvm/utils/gn/secondary/llvm/lib/Target/AMDGPU/BUILD.gn

@@ -160,6 +160,7 @@ static_library("LLVMAMDGPUCodeGen") {
     "AMDGPULibCalls.cpp",
     "AMDGPULibFunc.cpp",
     "AMDGPULowerBufferFatPointers.cpp",
+    "AMDGPULowerIntrinsics.cpp",
     "AMDGPULowerKernelArguments.cpp",
     "AMDGPULowerKernelAttributes.cpp",
     "AMDGPULowerModuleLDSPass.cpp",