refactor some code relating to pointer cast xforms, pulling it out of the codepath for unrelated casts.
refactor some code relating to pointer cast xforms, pulling it out of the codepath
for unrelated casts.


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@36511 91177308-0d34-0410-b5e6-96231b3b80d8

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