* module/ice-9/boot-9.scm (%cond-expand-features): Add srfi-16 and
srfi-30.
* doc/ref/srfi-modules.texi (SRFI-0): Add srfi-16 and srfi-30 to the
list of core features.
* module/srfi/srfi-16.scm: Remove call to 'cond-expand-provide'.
* module/ice-9/psyntax.scm (case-lambda, case-lambda*): Add
implementations of these, present in the base environment.
* module/ice-9/psyntax-pp.scm: Regenerated.
* module/srfi/srfi-16.scm (case-lambda): Replace the core's case-lambda
definition with our own. We're not quite ready to switch yet.