add ARM cmd line option to force always using virtual base regs when possible. Intended to help ease reproducing problems by increasing base register usage after heuristics for only using the when needed are in place.
add ARM cmd line option to force always using virtual base regs when possible.
Intended to help ease reproducing problems by increasing base register usage
after heuristics for only using the when needed are in place.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@111930 91177308-0d34-0410-b5e6-96231b3b80d8

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