[Dialect] Avoid repeated hash lookups (NFC) (#108137)

Author: kazutakahirata

mlir/lib/Dialect/Bufferization/IR/BufferizableOpInterface.cpp

@@ -465,9 +465,8 @@ bool AnalysisState::isValueRead(Value value) const {
 
   while (!workingSet.empty()) {
     OpOperand *uMaybeReading = workingSet.pop_back_val();
-    if (visited.contains(uMaybeReading))
+    if (!visited.insert(uMaybeReading).second)
       continue;
-    visited.insert(uMaybeReading);
 
     // Skip over all ops that neither read nor write (but create an alias).
     if (bufferizesToAliasOnly(*uMaybeReading))