gdb/

gdb/
	* symfile.c (download_write_size): Remove.
	(show_download_write_size): Remove.
	(load_section_callback): Don't use download_write_size.
	(_initialize_symfile): Don't register download_write_size.
	* NEWS: Mention 'download-write-size' removal.
gdb/doc/
	* gdb.texinfo (Target Commands): Remove
	'set download-write-size' and 'show download-write-size'.
gdb/testsuite/
	* config/monitor.exp (gdb_load): Remove support for obsolete
	download-write-size.
	* gdb.base/remote.exp: Likewise.  Update all callers of
	gdb_timed_load.