Fix reg mask slot test, and preserve LiveIntervals and VirtRegMap in the PBQP allocator. Fixes PR13945.
Fix reg mask slot test, and preserve LiveIntervals and VirtRegMap in the PBQP
allocator. Fixes PR13945.


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@165201 91177308-0d34-0410-b5e6-96231b3b80d8

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