The expander as a linklet will be instantiated once, so there's no
need to capture references in closures among functions within the
expander. Add a "static" linklet compilation mode to inline the
variable addresses that would otherwise be referenced via a closure.
Although the change is intended to speed up the expander by avoiding
some indrections, it also reduces the bytecode size of the expander.
Bitmaps that track which linklet variables are used in closures turn
out to have been about 25% of the expander's bytecode size, since the
linklet has so many definitions.
This commit merges changes that were developed in the "racket7" repo.
See that repo (which is no longer modified) for a more fine-grained
change history.
The commit includes experimental support for running Racket on Chez
Scheme, but that "CS" variant is not built by default.
