Fix review comments

Author: Leporacanthicus

flang/include/flang/Tools/CrossToolHelpers.h

@@ -23,18 +23,15 @@
 
 /// Configuriation for the MLIR to LLVM pass pipeline.
 struct MLIRToLLVMPassPipelineConfig {
-  MLIRToLLVMPassPipelineConfig(llvm::OptimizationLevel level) {
+  explicit MLIRToLLVMPassPipelineConfig(llvm::OptimizationLevel level) {
     OptLevel = level;
-    StackArrays = false;
-    Underscoring = true;
-    LoopVersioning = false;
-    DebugInfo = llvm::codegenoptions::NoDebugInfo;
   }
   llvm::OptimizationLevel OptLevel; ///< optimisation level
-  bool StackArrays; ///< convert memory allocations to alloca.
-  bool Underscoring; ///< add underscores to function names.
-  bool LoopVersioning; ///< Run the version loop pass.
-  llvm::codegenoptions::DebugInfoKind DebugInfo; ///< Debug info generation.
+  bool StackArrays = false; ///< convert memory allocations to alloca.
+  bool Underscoring = true; ///< add underscores to function names.
+  bool LoopVersioning = false; ///< Run the version loop pass.
+  llvm::codegenoptions::DebugInfoKind DebugInfo =
+      llvm::codegenoptions::NoDebugInfo; ///< Debug info generation.
 };
 
 struct OffloadModuleOpts {

flang/tools/bbc/bbc.cpp

@@ -368,7 +368,8 @@ static mlir::LogicalResult convertFortranSourceToMLIR(
     pm.addPass(std::make_unique<Fortran::lower::VerifierPass>());
 
     // Add O2 optimizer pass pipeline.
-    fir::createDefaultFIROptimizerPassPipeline(pm, llvm::OptimizationLevel::O2);
+    fir::createDefaultFIROptimizerPassPipeline(
+        pm, MLIRToLLVMPassPipelineConfig(llvm::OptimizationLevel::O2));
   }
 
   if (mlir::succeeded(pm.run(mlirModule))) {