[ARM] Tighten f64<->f16 conversion requirements


Fix missing Requires fields.

Patch by Bernard Ogden (bogden)

Reviewers: SjoerdMeijer, javed.absar, t.p.northover	

Reviewed By: t.p.northover

Differential Revision: https://reviews.llvm.org/D51631


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342061 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed