When we're determining what registers to coallesce, track the VNInfo IDs for the definitions that feed the PHI instructions.  We'll need these IDs in order to update LiveIntervals properly.
When we're determining what registers to coallesce, track the VNInfo IDs for the definitions that
feed the PHI instructions.  We'll need these IDs in order to update LiveIntervals properly.


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@48277 91177308-0d34-0410-b5e6-96231b3b80d8

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