Only collect subreg extracting copies for later coalescing. This also avoids fatal copies from physregs.
Only collect subreg extracting copies for later coalescing.
This also avoids fatal copies from physregs.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@108061 91177308-0d34-0410-b5e6-96231b3b80d8

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