Driver: Add Arg::getAsString and use when dumping arguments to
diagnostics.
 - This ensures that the whole argument and values are printed,
   instead of just the option name.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@67366 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed