illumos gate

While the save-args matching accepts that the actual argument saving prologue may be interleaved with other unrelated instructions by the insn scheduler, it does not expect that this may be true of actually saving the frame pointer and establishing the frame.

It really needs to allow for this too, as insns unrelated to the frame may unfortunately get scheduled before, or amongst, the classic prologue by optimization.

We should also increase the maximum distance into the function we're willing to scan.