* module/Makefile.am: Add tree-il sources.
* module/ice-9/compile-psyntax.scm: Adjust for sc-expand producing
tree-il in compile mode.
* module/ice-9/psyntax.scm: Switch from expand-support to tree-il for
generating output in compile mode. Completely generate tree-il -- the
output wasn't Scheme before, but now it's completely not Scheme.
* module/ice-9/psyntax-pp.scm: Regenerated.
* module/language/scheme/compile-ghil.scm: Strip structures using
tree-il, not expand-support.
* module/language/tree-il.scm:
* module/language/tree-il/spec.scm
* module/language/tree-il/compile-glil.scm: New language. It will compile
to GLIL, though it doesn't yet.
