llvm-uselistorder: Check the correct flag for assembly

This is part of PR5680.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214122 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-uselistorder: Add -save-temps option

This is part of PR5680.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214123 91177308-0d34-0410-b5e6-96231b3b80d8