Merging r244322:

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r244322 | thomas.stellard | 2015-08-07 11:34:30 -0400 (Fri, 07 Aug 2015) | 8 lines

AMDGPU/SI: v_mac_legacy_f32 does not exist on VI

Reviewers: arsenm

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11810

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llvm-svn: 253232