Add range changing to STABS parsing functions, in order to prevent buffer overruns.

Add range changing to STABS parsing functions, in order to prevent buffer overruns.

	PR 22955
	* stabs.c (parse_number): Add p_end parameter and use it to check
	the validity of the pp parameter.  Add checks to prevent walking
	off the end of the string buffer.
	(parse_stab_string): Likewise.
	(parse_stab_type): Likewise.
	(parse_stab_type_number): Likewise.
	(parse_stab_range_type): Likewise.
	(parse_stab_sun_builtin_type): Likewise.
	(parse_stab_sun_floating_type): Likewise.
	(parse_stab_enum_type): Likewise.
	(parse_stab_struct_type): Likewise.
	(parse_stab_baseclasses): Likewise.
	(parse_stab_struct_fields): Likewise.
	(parse_stab_cpp_abbrev): Likewise.
	(parse_stab_one_struct_field): Likewise.
	(parse_stab_members): Likewise.
	(parse_stab_tilde_field): Likewise.
	(parse_stab_array_type): Likewise.
	* parse_stab: Compute the end of the string and then pass it on to
	individual parser functions.