* * boot-9.scm (primitive-macro?): New procedure.

*	* boot-9.scm (primitive-macro?): New procedure.

	* slib.scm: Added hack which transfers syntactic information from
	the builtin variable `define' to the slib version if module (ice-9
	syncase) has been loaded.  This is necessary to get correct
	expansion inside the slib module.

	* psyntax.ss (build-let, build-named-let): New output
	constructors.
	(build-lexical-var): Seed gensym with symbolic name.
	(self-evaluating?): Add keywords among self-evaluating types.
	(let): New core form.
	(if): Removed from core language.
	(or, and, let, cond): Removed syntactic definitions.
	(sc-expand3): New procedure: Expander which takes optional mode
	and eval-syntactic-expanders-when arguments.

	* syncase.scm (psyncomp): New procedure: Recompiles psyntax.pp.
	Should be used inside the (ice-9 syncase) module with (use-syntax
	syncase) and with the current directory containing the psyntax.ss
	source.
	Added hack to transfer syntactic information from the builtin
	variable `define' to the slib version if module (ice-9 slib) has
	been loaded.