cpphash.c (cpp_forall_identifiers): Add context variable for callback routine.

cpphash.c (cpp_forall_identifiers): Add context variable for callback routine.

	* cpphash.c (cpp_forall_identifiers): Add context variable
	for callback routine.
	* cppmain.c (dump_macro): Update to match cpp_forall_identifiers
	change.
	(main): Call cpp_forall_identifiers with null context.
	* cpplib.h (cpp_forall_identifiers): Update prototype.

	* cppmain.c: Make `parse_in' and `print' static.

From-SVN: r37119