[ExecutionEngine] Avoid repeated hash lookups (NFC) (llvm#110621)

Author: kazutakahirata

llvm/lib/ExecutionEngine/Orc/Debugging/VTuneSupportPlugin.cpp

@@ -39,12 +39,12 @@ static VTuneMethodBatch getMethodBatch(LinkGraph &G, bool EmitDebugInfo) {
 
   auto GetStringIdx = [Deduplicator = StringMap<uint32_t>(),
                        &Batch](StringRef S) mutable {
-    auto I = Deduplicator.find(S);
-    if (I != Deduplicator.end())
-      return I->second;
-
-    Batch.Strings.push_back(S.str());
-    return Deduplicator[S] = Batch.Strings.size();
+    auto [I, Inserted] = Deduplicator.try_emplace(S);
+    if (Inserted) {
+      Batch.Strings.push_back(S.str());
+      I->second = Batch.Strings.size();
+    }
+    return I->second;
   };
   for (auto Sym : G.defined_symbols()) {
     if (!Sym->isCallable())