Merging r311623:

Merging r311623:
------------------------------------------------------------------------
r311623 | hans | 2017-08-23 18:08:27 -0700 (Wed, 23 Aug 2017) | 11 lines

[DAG] Fix Node Replacement in PromoteIntBinOp

When one operand is a user of another in a promoted binary operation
we may replace and delete the returned value before returning
triggering an assertion. Reorder node replacements to prevent this.

Fixes PR34137.

Landing on behalf of Nirav.

Differential Revision: https://reviews.llvm.org/D36581
------------------------------------------------------------------------

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_50@311670 91177308-0d34-0410-b5e6-96231b3b80d8