Disable formation of rlwinm instructions from SRA bases.  This fixes the 177.mesa failure from last night, and fixes the CodeGen/PowerPC/2005-10-08-ArithmeticRotate.ll regression test I added. If this code cannot be fixed, it should be removed for good, but I'll leave it to Nate to decide its fate.
Disable formation of rlwinm instructions from SRA bases.  This fixes
the 177.mesa failure from last night, and fixes the
CodeGen/PowerPC/2005-10-08-ArithmeticRotate.ll regression test I added.
If this code cannot be fixed, it should be removed for good, but I'll leave
it to Nate to decide its fate.


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@23670 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-llvm,apple/swift-llvm,chubbymaggie/asap,GPUOpen-Drivers/llvm,llvm-mirror/llvm,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap,apple/swift-llvm,chubbymaggie/asap,apple/swift-llvm,apple/swift-llvm,dslab-epfl/asap,dslab-epfl/asap,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,chubbymaggie/asap,dslab-epfl/asap,llvm-mirror/llvm,chubbymaggie/asap,dslab-epfl/asap,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,chubbymaggie/asap,llvm-mirror/llvm,dslab-epfl/asap,GPUOpen-Drivers/llvm,chubbymaggie/asap