[GlobalISel] Add IRTranslator support for G_FRINT

Add it as a simple intrinsic, update arm64-irtranslator.ll.

Differential Revision: https://reviews.llvm.org/D60893

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358787 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed