[driver] In general, the driver claims redundant args and uses the last arg.
However, the '-x' option has special handling and wasn't following this
paradigm.  Fix it to do so by claiming the arg as we parse the '-x' option.
rdar://11203340


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@154231 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed