Merging r275935:

Merging r275935:
------------------------------------------------------------------------
r275935 | arsenm | 2016-07-18 17:35:22 -0700 (Mon, 18 Jul 2016) | 6 lines

AMDGPU/SI: Fix SI scheduler refcount issue

Without this fix, releaseSuccessors when InOrOutBlock is
false could release SUs outside the schedule BasicBlock.

Patch by Axel Davy
------------------------------------------------------------------------

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_39@276116 91177308-0d34-0410-b5e6-96231b3b80d8