Convert dwarf2_section_buffer_overflow_complaint to a method

Convert dwarf2_section_buffer_overflow_complaint to a method

This changes dwarf2_section_buffer_overflow_complaint to be a method
on dwarf2_section_info.

gdb/ChangeLog
2020-03-26  Tom Tromey  <tom@tromey.com>

	* dwarf2/section.h (struct dwarf2_section_info)
	<overload_complaint>: Declare.
	(dwarf2_section_buffer_overflow_complaint): Don't declare.
	* dwarf2/section.c (dwarf2_section_info::overflow_complaint):
	Rename from dwarf2_section_buffer_overflow_complaint.
	* dwarf2/read.c (skip_one_die, partial_die_info::read)
	(skip_form_bytes, dwarf_decode_macro_bytes): Update.