Reapply commit 112702 which was speculatively reverted by echristo. Original commit message: Use the SSAUpdator to turn calls to eh.exception that are not in a landing pad into uses of registers rather than loads from a stack slot.  Doesn't touch the 'orrible hack code - Bill needs to persuade me harder :)
Reapply commit 112702 which was speculatively reverted by echristo.
Original commit message:
Use the SSAUpdator to turn calls to eh.exception that are not in a
landing pad into uses of registers rather than loads from a stack
slot.  Doesn't touch the 'orrible hack code - Bill needs to persuade
me harder :)


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@112952 91177308-0d34-0410-b5e6-96231b3b80d8

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