[tools] Don't call StringRef::str() when calling StringMap::find (NFC) (#113119)

StringMap::find takes StringRef.  We don't need to create an instance
of std::string from StringRef only to convert it right back to
StringRef.

Author: kazutakahirata

llvm/tools/llvm-profdata/llvm-profdata.cpp

@@ -1297,7 +1297,7 @@ adjustInstrProfile(std::unique_ptr<WriterContext> &WC,
       } else {
         auto NewName = StaticFuncMap.find(Name);
         if (NewName != StaticFuncMap.end()) {
-          It = InstrProfileMap.find(NewName->second.str());
+          It = InstrProfileMap.find(NewName->second);
           if (NewName->second != DuplicateNameStr) {
             NewRootName = &NewName->second;
           }
@@ -1382,7 +1382,7 @@ adjustInstrProfile(std::unique_ptr<WriterContext> &WC,
     if (It == InstrProfileMap.end()) {
       auto NewName = StaticFuncMap.find(Name);
       if (NewName != StaticFuncMap.end()) {
-        It = InstrProfileMap.find(NewName->second.str());
+        It = InstrProfileMap.find(NewName->second);
         if (NewName->second == DuplicateNameStr) {
           WithColor::warning()
               << "Static function " << Name

llvm/tools/llvm-readtapi/llvm-readtapi.cpp

@@ -382,7 +382,7 @@ static void stubifyDirectory(const StringRef InputPath, Context &Ctx) {
     // libraries to stubify.
     StringRef LibToCheck = Found->second;
     for (int i = 0; i < 20; ++i) {
-      auto LinkIt = SymLinks.find(LibToCheck.str());
+      auto LinkIt = SymLinks.find(LibToCheck);
       if (LinkIt != SymLinks.end()) {
         for (auto &SymInfo : LinkIt->second) {
           SmallString<PATH_MAX> LinkSrc(SymInfo.SrcPath);