Merging r250324:

Merging r250324:

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r250324 | wschmidt | 2015-10-14 16:45:00 -0400 (Wed, 14 Oct 2015) | 10 lines

[PowerPC] Fix invalid lxvdsx optimization (PR25157)

PR25157 identifies a bug where a load plus a vector shuffle is
incorrectly converted into an LXVDSX instruction.  That optimization
is only valid if the load is of a doubleword, and in the noted case,
it was not.  This corrects that problem.

Joint patch with Eric Schweitz, who provided the bugpoint-reduced test
case.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_37@252483 91177308-0d34-0410-b5e6-96231b3b80d8