* module/Makefile.am (SOURCES): Reorganize so GHIL is compiled last,
along with ecmascript.
* module/language/scheme/spec.scm: Remove references to GHIL, as it's
bitrotten and obsolete..
* module/language/tree-il.scm (make-tree-il-folder): Rework so that we
only have down and up procs, and call down and up on each element.
* module/language/tree-il/analyze.scm (analyze-lexicals): Fix a thinko
handling let-values.
* module/language/tree-il/fix-letrec.scm: Actually implement fixing
letrec. The resulting code will perform better, but violations of the
letrec restriction are not detected. This behavior is allowed by the
spec, but it is undesirable. Perhaps that will be fixed later.
* module/language/tree-il/inline.scm (inline!): Fix a case in which
((lambda args foo)) would be erroneously inlined to foo. Remove empty
let, letrec, and fix statements.
* module/language/tree-il/primitives.scm (effect-free-primitive?): New
public predicate.
* libguile/vm-i-system.c (fix-closure): New instruction, for wiring
together fixpoint procedures.
* module/Makefile.am (TREE_IL_LANG_SOURCES): Add fix-letrec.scm.
* module/language/glil/compile-assembly.scm (glil->assembly): Reindent
the <glil-lexical> case, and handle 'fix for locally-bound vars.
* module/language/tree-il.scm (<fix>): Add the <fix> tree-il type and
accessors, for fixed-point bindings. This IL construct is taken from
the Waddell paper.
(parse-tree-il, unparse-tree-il, tree-il->scheme, tree-il-fold)
(pre-order!, post-order!): Update for <fix>.
* module/language/tree-il/analyze.scm (analyze-lexicals): Update for
<fix>. The difference here is that the bindings may not be assigned,
and are not marked as such. They are not boxed.
(report-unused-variables): Update for <fix>.
* module/language/tree-il/compile-glil.scm (flatten): Compile <fix> to
GLIL.
* module/language/tree-il/fix-letrec.scm: A stub implementation of
fixing letrec -- will flesh out in a separate commit.
* module/language/tree-il/inline.scm: Fix license, it was mistakenly
added with LGPL v2.1+.
* module/language/tree-il/optimize.scm (optimize!): Run the fix-letrec!
pass.
