Make breakpoint_re_set_one work with overloaded member functions,

	Make breakpoint_re_set_one work with overloaded member functions,
	`b 123' and `b foo' if foo is a static function.
	* symtab.c (decode_line_1, decode_line_2):  New argument `canonical'
	to return canonical line specs if requested by the caller.
	* breakpoint.c, source.c, symtab.c, symtab.h:  Change prototypes and
	callers accordingly.
	* symtab.c (build_canonical_line_spec):  New helper function which
	constructs the canonical line spec.
	* breakpoint.c (break_command_1):  Use canonical line spec instead
	of command string as addr_string if necessary.
	* source.c (line_info):  Fix storage leak.