[X86] VRNDSCALE* folding from masked and scalar ffloor and fceil patterns

This patch handles back-end folding of generic patterns created by lowering the
X86 rounding intrinsics to native IR in cases where the instruction isn't a
straightforward packed values rounding operation, but a masked operation or a
scalar operation.

Differential Revision: https://reviews.llvm.org/D45203


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335037 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed