[ARM] Run ARMParallelDSP in the IRPasses phase

Run EarlyCSE before ParallelDSP and do this in the backend IR opt
phase.

Differential Revision: https://reviews.llvm.org/D59257


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356130 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed