* gc-benchmarks/gc-profile.scm (*iteration-count*): New parameter.
(run-benchmark): Moved from `twobit-compat.scm'. Honor
`*iteration-count*'.
(%options): Add `--iterations'.
(show-help): Document it.
(main): Parameterize `*iteration-count*'.
* gc-benchmarks/gc-profile.scm: Load "twobit-compat.scm".
(save-directory-excursion, load-larceny-benchmark): New procedures.
(%options): New variable.
(show-help, parse-args): New procedures.
(main): Use `parse-args' and `load-larceny-benchmark'.