Merging r266217:

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r266217 | niravd | 2016-04-13 10:27:26 -0700 (Wed, 13 Apr 2016) | 12 lines

Cleanup Store Merging in UseAA case

This patch fixes a bug (PR26827) when using anti-aliasing in store
merging. This sets the chain users of the component stores to point to
the new store instead of the component stores chain parent.

Reviewers: jyknight

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D18909

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llvm-svn: 271216