[flang] Fix for compilation problems caused by D79578

[PeteSteinfeld]

Summary

D79578 changed the name of an mlir namespace from "loop" to "scf" and also changed the name of one of its members. This change allows flang to build without errors and pass all tests.

[tskeith]

Looks great

[clementval]

This was addressed in D79723

[schweitz]

Thanks for the fix.

[PeteSteinfeld]

Superseded by D79723.

flang/include/flang/Optimizer/Dialect/FIRDialect.h

 };
 
 /// Register the dialect with MLIR
 inline void registerFIR() {
   // we want to register exactly once
   [[maybe_unused]] static bool init_once = [] {
     mlir::registerDialect<mlir::AffineDialect>();
     mlir::registerDialect<mlir::LLVM::LLVMDialect>();
-    mlir::registerDialect<mlir::loop::LoopOpsDialect>();
+    mlir::registerDialect<mlir::scf::SCFDialect>();
     mlir::registerDialect<mlir::StandardOpsDialect>();
     mlir::registerDialect<mlir::vector::VectorDialect>();
     mlir::registerDialect<FIROpsDialect>();
     return true;
   }();
 }
 
 /// Register the standard passes we use. This comes from registerAllPasses(),