[DebugInfo] Avoid repeated hash lookups (NFC) (llvm#110620)

Author: kazutakahirata

llvm/lib/DebugInfo/LogicalView/Core/LVCompare.cpp

@@ -312,8 +312,9 @@ Error LVCompare::execute(LVReader *ReferenceReader, LVReader *TargetReader) {
 
       // We need to find an insertion point in the reference scopes tree.
       Parent = Element->getParentScope();
-      if (ScopeLinks.find(Parent) != ScopeLinks.end()) {
-        LVScope *InsertionPoint = ScopeLinks[Parent];
+      auto It = ScopeLinks.find(Parent);
+      if (It != ScopeLinks.end()) {
+        LVScope *InsertionPoint = It->second;
         LLVM_DEBUG({
           dbgs() << "Inserted at: "
                  << hexSquareString(InsertionPoint->getOffset()) << "\n";