[flang] Fix build after D143339

[springerm]

Summary

This change silences a compiler warning: base class should be explictily initialized in the copy constructor.

[kiranchandramohan]

Nit: Could you add a line in the summary what this change does?

flang/include/flang/Optimizer/Builder/FIRBuilder.h

47

Is the same change required here?

[springerm]

address comments

[springerm]

flang/include/flang/Optimizer/Builder/FIRBuilder.h

47

The build failure was due to a warning about the copy constructor. So it's probably not needed. But maybe better to add here as well.

[PeteSteinfeld]

Thanks for doing this!

With this change, flang builds correctly and passes all tests.

[jeanPerier]

LGTM

flang/include/flang/Optimizer/Builder/FIRBuilder.h

 /// Extends the MLIR OpBuilder to provide methods for building common FIR
 /// patterns.
 class FirOpBuilder : public mlir::OpBuilder, public mlir::OpBuilder::Listener {
 public:
   explicit FirOpBuilder(mlir::Operation *op, const fir::KindMapping &kindMap)
       : OpBuilder{op, /*listener=*/this}, kindMap{kindMap} {}
   explicit FirOpBuilder(mlir::OpBuilder &builder,
                         const fir::KindMapping &kindMap)
-      : OpBuilder{builder}, kindMap{kindMap} {
+      : OpBuilder(builder), OpBuilder::Listener(), kindMap{kindMap} {
     setListener(this);
   }
 
   // The listener self-reference has to be updated in case of copy-construction.
   FirOpBuilder(const FirOpBuilder &other)
-      : OpBuilder{other}, kindMap{other.kindMap}, fastMathFlags{
-                                                      other.fastMathFlags} {
+      : OpBuilder(other), OpBuilder::Listener(), kindMap{other.kindMap},
+        fastMathFlags{other.fastMathFlags} {
     setListener(this);
   }
 
   /// Get the current Region of the insertion point.
   mlir::Region &getRegion() { return *getBlock()->getParent(); }
 
   /// Get the current Module
   mlir::ModuleOp getModule() {