Fix a problem where 'process launch' was not correctly re-quoting arguments...

Fix a problem where 'process launch' was not correctly re-quoting arguments for the inferior process when handing them down for the actual launch

This covers most of rdar://20490076, but leaves one corner case still open - namely the case where we try to have arguments of the form foo\ bar (unquoted, but slashed) go through argdumper

llvm-svn: 234554