Fix internal error in gold when -Map and --compress-debug-sections are used

Fix internal error in gold when -Map and --compress-debug-sections are used
together.

gold/
	* mapfile.cc (Mapfile::print_input_section): Print uncompressed sizes.
	(Mapfile::print_output_data): Use current_data_size() to avoid
	assert for sections requiring postprocessing; if address is not valid,
	print 0.
	(Mapfile::print_output_section): Use current_data_size(); print note
	that addresses and sizes are before compression.