[flang][HLFIR][NFC] Reduce intrinsic lowering pass boilerplate (#93062)

The pass constructor can be generated automatically.

This pass is module-level and then runs on all relevant intrinsic
operations inside of the module, no matter what top level operation they
are inside of.

Author: tblah

flang/include/flang/Optimizer/HLFIR/Passes.h

@@ -24,7 +24,6 @@ namespace hlfir {
 
 std::unique_ptr<mlir::Pass> createConvertHLFIRtoFIRPass();
 std::unique_ptr<mlir::Pass> createBufferizeHLFIRPass();
-std::unique_ptr<mlir::Pass> createLowerHLFIRIntrinsicsPass();
 
 #define GEN_PASS_REGISTRATION
 #include "flang/Optimizer/HLFIR/Passes.h.inc"

flang/include/flang/Optimizer/HLFIR/Passes.td

@@ -29,7 +29,6 @@ def OptimizedBufferization : Pass<"opt-bufferization"> {
 
 def LowerHLFIRIntrinsics : Pass<"lower-hlfir-intrinsics", "::mlir::ModuleOp"> {
   let summary = "Lower HLFIR transformational intrinsic operations";
-  let constructor = "hlfir::createLowerHLFIRIntrinsicsPass()";
 }
 
 def LowerHLFIROrderedAssignments : Pass<"lower-hlfir-ordered-assignments", "::mlir::ModuleOp"> {

flang/include/flang/Tools/CLOptions.inc

@@ -328,7 +328,7 @@ inline void createHLFIRToFIRPassPipeline(
         pm, hlfir::createOptimizedBufferization);
   }
   pm.addPass(hlfir::createLowerHLFIROrderedAssignments());
-  pm.addPass(hlfir::createLowerHLFIRIntrinsicsPass());
+  pm.addPass(hlfir::createLowerHLFIRIntrinsics());
   pm.addPass(hlfir::createBufferizeHLFIRPass());
   pm.addPass(hlfir::createConvertHLFIRtoFIRPass());
 }

flang/lib/Optimizer/HLFIR/Transforms/LowerHLFIRIntrinsics.cpp

@@ -468,13 +468,6 @@ class LowerHLFIRIntrinsics
     : public hlfir::impl::LowerHLFIRIntrinsicsBase<LowerHLFIRIntrinsics> {
 public:
   void runOnOperation() override {
-    // TODO: make this a pass operating on FuncOp. The issue is that
-    // FirOpBuilder helpers may generate new FuncOp because of runtime/llvm
-    // intrinsics calls creation. This may create race conflict if the pass is
-    // scheduled on FuncOp. A solution could be to provide an optional mutex
-    // when building a FirOpBuilder and locking around FuncOp and GlobalOp
-    // creation, but this needs a bit more thinking, so at this point the pass
-    // is scheduled on the moduleOp.
     mlir::ModuleOp module = this->getOperation();
     mlir::MLIRContext *context = &getContext();
     mlir::RewritePatternSet patterns(context);
@@ -504,7 +497,3 @@ class LowerHLFIRIntrinsics
   }
 };
 } // namespace
-
-std::unique_ptr<mlir::Pass> hlfir::createLowerHLFIRIntrinsicsPass() {
-  return std::make_unique<LowerHLFIRIntrinsics>();
-}