[Driver] Fix indentation.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@171909 91177308-0d34-0410-b5e6-96231b3b80d8
[lld] Add support for -mllvm.

There is no way to test this at the moment because the options are not
processed until the link starts, and we can't pass an empty file.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@171910 91177308-0d34-0410-b5e6-96231b3b80d8