* Convert to be a MachineFunctionPass instance * Use new FunctionFrameInfo object to manage stack slots instead of doing   it directly * Adjust to new MRegisterInfo API * Don't take a TM as a ctor argument * Don't keep track of which callee saved registers are modified * Don't emit prolog/epilog code or spill/restore code for callee saved regs * Use new allocation_order_begin/end iterators to simplify dramatically the   logic for picking registers to allocate * Machine PHI nodes can no longer contain constant arguments
* Convert to be a MachineFunctionPass instance
* Use new FunctionFrameInfo object to manage stack slots instead of doing
  it directly
* Adjust to new MRegisterInfo API
* Don't take a TM as a ctor argument
* Don't keep track of which callee saved registers are modified
* Don't emit prolog/epilog code or spill/restore code for callee saved regs
* Use new allocation_order_begin/end iterators to simplify dramatically the
  logic for picking registers to allocate
* Machine PHI nodes can no longer contain constant arguments

* Use a bitvector to keep track of registers used instead of a set
* Fix problem where explicitly referenced registers would be added to
  regsused set and never removed


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@5196 91177308-0d34-0410-b5e6-96231b3b80d8

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