[CodeGen] Avoid repeated hash lookups (NFC) (llvm#126672)

Author: kazutakahirata

clang/lib/CodeGen/CGOpenMPRuntime.cpp

@@ -1457,14 +1457,13 @@ void CGOpenMPRuntime::functionFinished(CodeGenFunction &CGF) {
     clearLocThreadIdInsertPt(CGF);
     OpenMPLocThreadIDMap.erase(CGF.CurFn);
   }
-  if (FunctionUDRMap.count(CGF.CurFn) > 0) {
-    for(const auto *D : FunctionUDRMap[CGF.CurFn])
+  if (auto I = FunctionUDRMap.find(CGF.CurFn); I != FunctionUDRMap.end()) {
+    for (const auto *D : I->second)
       UDRMap.erase(D);
-    FunctionUDRMap.erase(CGF.CurFn);
+    FunctionUDRMap.erase(I);
   }
-  auto I = FunctionUDMMap.find(CGF.CurFn);
-  if (I != FunctionUDMMap.end()) {
-    for(const auto *D : I->second)
+  if (auto I = FunctionUDMMap.find(CGF.CurFn); I != FunctionUDMMap.end()) {
+    for (const auto *D : I->second)
       UDMMap.erase(D);
     FunctionUDMMap.erase(I);
   }