[NFC] Remove unused var (#14565)

Causing build failure with `-Werror`.

Author: jsji

clang/tools/clang-linker-wrapper/ClangLinkerWrapper.cpp

@@ -853,7 +853,6 @@ static void addBackendOptions(const ArgList &Args,
 static Expected<StringRef> runAOTCompileIntelCPU(StringRef InputFile,
                                                  const ArgList &Args) {
   const llvm::Triple Triple(Args.getLastArgValue(OPT_triple_EQ));
-  StringRef Arch(Args.getLastArgValue(OPT_arch_EQ));
   SmallVector<StringRef, 8> CmdArgs;
   Expected<std::string> OpenCLAOTPath =
       findProgram("opencl-aot", {getMainExecutable("opencl-aot")});

llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp

@@ -881,7 +881,6 @@ struct AddressSanitizer {
   FunctionCallee AsanSetShadowStaticLocalFunc;
   FunctionCallee AsanSetShadowDynamicLocalFunc;
   Constant *AsanShadowGlobal;
-  Constant *AsanShadowDevicePrivate;
   StringMap<GlobalVariable *> GlobalStringMap;
   Constant *AsanLaunchInfo;