The patch fixes (base, index, offset) match.

Summary:
Instead of matching:
  (a + i) + 1 -> (a + i, undef, 1)
Now it matches:
  (a + i) + 1 -> (a, i, 1)

Reviewers: rengolin

Differential Revision: http://reviews.llvm.org/D26367

From: Evgeny Stupachenko <evstupac@gmail.com>
llvm-svn: 291012