if we have a phi translation failure of the start block, return *just* a clobber of the start block, not other  random stuff as well.
if we have a phi translation failure of the start block,
return *just* a clobber of the start block, not other 
random stuff as well.


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@61026 91177308-0d34-0410-b5e6-96231b3b80d8

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