Merging r259645:

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r259645 | nemanjai | 2016-02-03 04:53:38 -0800 (Wed, 03 Feb 2016) | 4 lines

Fix for PR 26381

Simple fix - Constant values were not being sign extended in FastIsel.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_38@259698 91177308-0d34-0410-b5e6-96231b3b80d8