Revert r344693 ("[ARM] bottom-top mul support in ARMParallelDSP")

Still causing failures on the polly-aosp buildbot; I'll follow up
with a reduced testcase.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344752 91177308-0d34-0410-b5e6-96231b3b80d8
25 files changed