* preliminaries for code generation logic

* preliminaries for code generation logic

2005-05-05  Frank Ch. Eigler  <fche@redhat.com>

	* parse.cxx (parse): Add helper methods.
	(lexer::scan, parse_assignment): Parse "<<<" operator.  Fix assignment
	associativity.
	(parse_symbol): Permit function with empty arg list.
	(parse_global, parse_statement, parse_functiondecl): Expect
	unconsumed leading keyword.
	(parse_global): Don't use ";" termination.
	* parse.h: Corresponding changes.
	* staptree.cxx (binary_expression::resolve_types): Fix <<<
	type inference.
	(translator_output): Improve pretty-printing.
	(*): Add general visitors to statement/expression types.
	* staptree.h: Corresponding changes.  Tweak symresolution_info fields.
	Add semantic_error class.
	* semtest.cxx: Adapt to this.
	* testsuite/parseok/two.stp, semok/*.stp: Adapt to syntax changes.