[x86][AVX512] Lowering Broadcastm intrinsics to LLVM IR

This patch, together with a matching clang patch (https://reviews.llvm.org/D38683), implements the lowering of X86 broadcastm intrinsics to IR.

Differential Revision: https://reviews.llvm.org/D38684

Change-Id: I709ac0b34641095397e994c8ff7e15d1315b3540

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317458 91177308-0d34-0410-b5e6-96231b3b80d8
10 files changed