[gn build] Port 737c4a2

Author: llvmgnsyncbot

llvm/utils/gn/secondary/clang/lib/CodeGen/BUILD.gn

@@ -65,9 +65,7 @@ static_library("CodeGen") {
     "CGObjCRuntime.cpp",
     "CGOpenCLRuntime.cpp",
     "CGOpenMPRuntime.cpp",
-    "CGOpenMPRuntimeAMDGCN.cpp",
     "CGOpenMPRuntimeGPU.cpp",
-    "CGOpenMPRuntimeNVPTX.cpp",
     "CGRecordLayoutBuilder.cpp",
     "CGStmt.cpp",
     "CGStmtOpenMP.cpp",