Remove dead debug option -disable-rematerialization.
Remove dead debug option -disable-rematerialization.

Remat has been stable for years, and it isn't done by
LiveIntervalAnalysis any longer. (See LiveRangeEdit).

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@158079 91177308-0d34-0410-b5e6-96231b3b80d8

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