[clang] [flang] [flang] add -floop-interchange and enable it with opt levels (PR #140182)

[Kiran Chandramohan via cfe-commits]

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@@ -421,7 +421,8 @@ static void CheckSubscripts(
 
 static void CheckSubscripts(
     semantics::SemanticsContext &context, CoarrayRef &ref) {
-  const Symbol &coarraySymbol{ref.GetBase().GetLastSymbol()};
+  const auto &base = ref.GetBase();
+  const Symbol &coarraySymbol{base.GetLastSymbol()};
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kiranchandramohan wrote:

Nit: Is this an unrelated change?

https://github.com/llvm/llvm-project/pull/140182