[Flang] responds to Clang Tidy feedback (#87847)

Line 267: performance-unnecessary-copy-initialization
Line 592: readability-container-size-empty

Author: cjdb

clang/lib/Driver/ToolChains/Flang.cpp

@@ -264,7 +264,7 @@ static void addVSDefines(const ToolChain &TC, const ArgList &Args,
   CmdArgs.push_back(Args.MakeArgString("-D_MSC_FULL_VER=" + Twine(ver)));
   CmdArgs.push_back(Args.MakeArgString("-D_WIN32"));
 
-  llvm::Triple triple = TC.getTriple();
+  const llvm::Triple &triple = TC.getTriple();
   if (triple.isAArch64()) {
     CmdArgs.push_back("-D_M_ARM64=1");
   } else if (triple.isX86() && triple.isArch32Bit()) {
@@ -589,7 +589,7 @@ static void addFloatingPointOptions(const Driver &D, const ArgList &Args,
 
   if (!HonorINFs && !HonorNaNs && AssociativeMath && ReciprocalMath &&
       ApproxFunc && !SignedZeros &&
-      (FPContract == "fast" || FPContract == "")) {
+      (FPContract == "fast" || FPContract.empty())) {
     CmdArgs.push_back("-ffast-math");
     return;
   }