[llvm-ifs] Avoid repeated map lookups (NFC) (#109750)

Author: kazutakahirata

llvm/tools/llvm-ifs/llvm-ifs.cpp

@@ -441,12 +441,9 @@ int llvm_ifs_main(int argc, char **argv, const llvm::ToolContext &) {
     }
 
     for (auto Symbol : TargetStub->Symbols) {
-      auto SI = SymbolMap.find(Symbol.Name);
-      if (SI == SymbolMap.end()) {
-        SymbolMap.insert(
-            std::pair<std::string, IFSSymbol>(Symbol.Name, Symbol));
+      auto [SI, Inserted] = SymbolMap.try_emplace(Symbol.Name, Symbol);
+      if (Inserted)
         continue;
-      }
 
       assert(Symbol.Name == SI->second.Name && "Symbol Names Must Match.");