[Clang] Replace cc1 options '-mdisable-fp-elim' and '-momit-leaf-frame-pointer'

with '-mframe-pointer'

After D56351 and D64294, frame pointer handling is migrated to tri-state
(all, non-leaf, none) in clang driver and on the function attribute.
This patch makes the frame pointer handling cc1 option tri-state.

Reviewers: chandlerc, rnk, t.p.northover, MaskRay

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D56353

llvm-svn: 366645