[flang] [llvm] [flang][llvm][OpenMP][OpenACC] Add implicit casts to omp.atomic and acc.atomic (PR #131603)

[Kiran Chandramohan via llvm-commits]

================
@@ -103,6 +104,61 @@ static void processOmpAtomicTODO(mlir::Type elementType,
   }
 }
 
+/// Emits an implicit cast for atomic statements
+static void emitImplicitCast(Fortran::lower::AbstractConverter &converter,
+                             mlir::Location loc, mlir::Value &fromAddress,
+                             mlir::Value &toAddress, mlir::Type &elementType) {
+  if (fromAddress.getType() == toAddress.getType())
+    return;
+  fir::FirOpBuilder &builder = converter.getFirOpBuilder();
+  mlir::Value alloca = builder.create<fir::AllocaOp>(
+      loc, fir::unwrapRefType(toAddress.getType()));
+  mlir::Value loadedVal = builder.create<fir::LoadOp>(loc, fromAddress);
+  mlir::Type toType = fir::unwrapRefType(toAddress.getType());
+  mlir::Type fromType = fir::unwrapRefType(fromAddress.getType());
+  if (!fir::isa_complex(toType) && !fir::isa_complex(fromType)) {
+    loadedVal = builder.create<fir::ConvertOp>(
+        loc, fir::unwrapRefType(toAddress.getType()), loadedVal);
----------------
kiranchandramohan wrote:

```suggestion
    loadedVal = builder.create<fir::ConvertOp>(
        loc, toType, loadedVal);
```

https://github.com/llvm/llvm-project/pull/131603