Move arglist_len et al to parser_state

Move arglist_len et al to parser_state

This moves arglist_len, start_arglist, and end_arglist to
parser_state.

gdb/ChangeLog
2019-04-04  Tom Tromey  <tom@tromey.com>

	* parser-defs.h (struct parser_state) <start_arglist,
	end_arglist>: New methods.
	<arglist_len, m_funcall_chain>: New members.
	(arglist_len, start_arglist, end_arglist): Don't declare.
	* parse.c (arglist_len, funcall_chain): Remove global.
	(start_arglist, end_arglist): Remove functions.
	(parse_exp_in_context): Update.
	* p-exp.y: Update rules.
	* m2-exp.y: Update rules.
	* go-exp.y: Update rules.
	* f-exp.y: Update rules.
	* d-exp.y: Update rules.
	* c-exp.y: Update rules.