Bug/case fixes:

(1) select: Ok to convert a pointer to a float or double.
(2) regalloc: Some MachineInstr* for caller-saving code before a call
    were being inserted before and after the call!
(3) Don't insert the caller-saving instructions in the
    MachineCodeForInstruction for the Call instruction.
    *All* instructions generated by register allocation need to be
    recorded in those maps, but it needs to be done uniformly.

llvm-svn: 7051