commits have had several major issues pointed out in review, and those
issues are not being addressed in a timely fashion. Furthermore, this
was all committed leading up to the v3.1 branch, and we don't need piles
of code with outstanding issues in the branch.

It is possible that not all of these commits were necessary to revert to
get us back to a green state, but I'm going to let the Hexagon
maintainer sort that out. They can recommit, in order, after addressing
the feedback.

Reverted commits, with some notes:

Primary commit r154616: HexagonPacketizer
  - There are lots of review comments here. This is the primary reason
    for reverting. In particular, it introduced large amount of warnings
    due to a bad construct in tablegen.
  - Follow-up commits that should be folded back into this when
    reposting:
    - r154622: CMake fixes
    - r154660: Fix numerous build warnings in release builds.
  - Please don't resubmit this until the three commits above are
    included, and the issues in review addressed.

Primary commit r154695: Pass to replace transfer/copy ...
  - Reverted to minimize merge conflicts. I'm not aware of specific
    issues with this patch.

Primary commit r154703: New Value Jump.
  - Primarily reverted due to merge conflicts.
  - Follow-up commits that should be folded back into this when
    reposting:
    - r154703: Remove iostream usage
    - r154758: Fix CMake builds
    - r154759: Fix build warnings in release builds
  - Please incorporate these fixes and and review feedback before
    resubmitting.

Primary commit r154829: Hexagon V5 (floating point) support.
  - Primarily reverted due to merge conflicts.
  - Follow-up commits that should be folded back into this when
    reposting:
    - r154841: Remove unused variable (fixing build warnings)

There are also accompanying Clang commits that will be reverted for
consistency.

llvm-svn: 155047