uselistorder: -mllvm -preserve-ll-use-list-order => -emit-llvm-uselists

Follow up to r234962, start respecting `-emit-llvm-uselists even for
LLVM assembly.  Note that the driver never passes this flag; this is
just a interface convenience/consistency for those using `-cc1`
directly.  This required LLVM r234969 (and predecessors).

llvm-svn: 234970
diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index a6d09f7..0d95fc1 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -607,7 +607,8 @@
     break;
 
   case Backend_EmitLL:
-    getPerModulePasses()->add(createPrintModulePass(*OS));
+    getPerModulePasses()->add(
+        createPrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists));
     break;
 
   default: