[flang] Pass unmodified std::vector as const reference (#95050)

cppcheck recommends that a std::vector argument be passed as a const
reference rather than by value.

Fixes #94929.

Author: klausler

flang/lib/Semantics/expression.cpp

@@ -172,7 +172,8 @@ class ArgumentAnalyzer {
   void Dump(llvm::raw_ostream &);
 
 private:
-  MaybeExpr TryDefinedOp(std::vector<const char *>, parser::MessageFixedText);
+  MaybeExpr TryDefinedOp(
+      const std::vector<const char *> &, parser::MessageFixedText);
   MaybeExpr TryBoundOp(const Symbol &, int passIndex);
   std::optional<ActualArgument> AnalyzeExpr(const parser::Expr &);
   std::optional<ActualArgument> AnalyzeVariable(const parser::Variable &);
@@ -4410,7 +4411,7 @@ MaybeExpr ArgumentAnalyzer::TryDefinedOp(
 }
 
 MaybeExpr ArgumentAnalyzer::TryDefinedOp(
-    std::vector<const char *> oprs, parser::MessageFixedText error) {
+    const std::vector<const char *> &oprs, parser::MessageFixedText error) {
   if (oprs.size() == 1) {
     return TryDefinedOp(oprs[0], error);
   }