Don't generate debug info for variable in target region.

These variables currently fail the llvm verifier tests as the scope
inside the variable is still point to the parent function of the
target region.

flang/lib/Optimizer/Transforms/AddDebugInfo.cpp

@@ -103,7 +103,11 @@ void AddDebugInfoPass::handleDeclareOp(fir::cg::XDeclareOp declOp,
   if (fir::isDummyArgument(declOp.getMemref())) {
     auto arg = llvm::cast<mlir::BlockArgument>(declOp.getMemref());
     argNo = arg.getArgNumber() + 1;
-  }
+  } else if (llvm::isa<mlir::BlockArgument>(declOp.getMemref()))
+    // FIXME: Handle arguments which are not dummy. These may be arguments
+    // to things like OpenMP regions. They may need some extra processing
+    // (e.g. to set the scope correctly).
+    return;
 
   auto tyAttr = typeGen.convertType(fir::unwrapRefType(declOp.getType()),
                                     fileAttr, scopeAttr, declOp.getLoc());