This patch introduces a VPInstructionToVPRecipe transformation, which
allows us to generate code for a VPInstruction based VPlan re-using the
existing infrastructure.
Reviewers: dcaballe, hsaito, mssimpso, hfinkel, rengolin, mkuper, javed.absar, sguggill
Reviewed By: dcaballe
Differential Revision: https://reviews.llvm.org/D46827
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334969 91177308-0d34-0410-b5e6-96231b3b80d8
