Adding -mtbm and -mno-tbm command line options to the clang front end for the

x86 TBM instruction set. Also adding a __TBM__ macro if the TBM feature is
enabled. Otherwise there should be no functionality change to existing features.

Phabricator code review is located here: http://llvm-reviews.chandlerc.com/D1693

llvm-svn: 191326