[m-dev.] faster higher order call

[Zoltan Somogyi]

> 		sparc-*)
> 			# NUM_REAL_REGS=10
> 			# but succip, sp, hp, maxfr, and curfr are real regs,
> 			# so subtract 5
> 			NUM_REAL_R_REGS=5

We originally figured out which virtual registers ought to be real regs
from the register reference counts of the small benchmark programs, half
of which were nondet. However, most of the programs we run these days
are almost entirely det, and may procedures have more than 5 arguments.
Maybe we should demote maxfr and/or curfr to non-real regs and make r6
and maybe r7 as real regs.

Zoltan.