Summary:
Because _Float16 was disabled for X86 targets the unit-tests started failing.
Extract the pieces for _Float16 and run theses tests under AArch64.
Reviewers: aaron.ballman, erichkeane, lebedev.ri
Reviewed By: erichkeane
Subscribers: javed.absar, xazax.hun, kristof.beyls, cfe-commits
Differential Revision: https://reviews.llvm.org/D57249
llvm-svn: 352231