[llvm-reduce] Set ShouldPreserveUseListOrder=true

When exporting textual IR during reduction the ShouldPreserveUseListOrder
parameter of the IR printer should be set to get predictable results.

Differential Revision: https://reviews.llvm.org/D118585

Author: markuslavin

llvm/tools/llvm-reduce/ReducerWorkItem.cpp

@@ -169,6 +169,7 @@ void ReducerWorkItem::print(raw_ostream &ROS, void *p) const {
     printMIR(ROS, *M);
     printMIR(ROS, *MF);
   } else {
-    M->print(ROS, nullptr);
+    M->print(ROS, /*AssemblyAnnotationWriter=*/nullptr,
+             /*ShouldPreserveUseListOrder=*/true);
   }
 }