* module/scripts/compile.scm (%options): Resurrect -O option and make it
follow GCC, more or less. The default is equivalent to -O2.
* module/language/cps/compile-bytecode.scm (lower-cps):
* module/language/cps/optimize.scm (optimize-higher-order-cps): Move
split-rec to run unconditionally for now, as closure conversion fails
without it.
(define-optimizer): Only verify the result if we are debugging, to
save time.
(cps-default-optimization-options): New exported procedure.
* module/language/tree-il/optimize.scm
(tree-il-default-optimization-options): New exported procedure.
* module/language/cps/peel-loops.scm: New pass. Only enabled if the
loop has one successor.
* module/language/cps/optimize.scm: Peel instead of doing LICM on
higher-order CPS, then LICM on first-order CPS.
* module/Makefile.am: Wire up new pass.
