Merging r195731:

Merging r195731:
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r195731 | rsandifo | 2013-11-26 10:53:16 +0000 (Tue, 26 Nov 2013) | 7 lines

[SystemZ] Fix incorrect use of RISBG for a zero-extended right shift

We would wrongly transform the testcase into the equivalent of an AND with 1.
The problem was that, when testing whether the shifted-in bits of the right
shift were significant, we used the width of the final zero-extended result
rather than the width of the shifted value.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_34@195736 91177308-0d34-0410-b5e6-96231b3b80d8