[Driver][cc1][cc1as] Call OptTable::PrintHelp with explicit " [options] file..."

Summary: This is to accommodate a change in llvm/lib/Option/OptTable.cpp D51009

Reviewers: rupprecht, alexshap, jhenderson

Reviewed By: rupprecht

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D51109

llvm-svn: 344098