* doc/options.texi (ToLower): Document.
	* opt-functions.awk (switch_bit_fields): Initialize cl_tolower
	field.
	* opts-common.c (decode_cmdline_option): Handle cl_tolower.
	* opts.h (cl_option): Add cl_tolower field.
	* config/rx/rx.c (rx_handle_option): Use strcmp of -mcpu=
	arguments with lowercase strings.
	* config/rx/rx.opt (mcpu=): Add ToLower.
	* config/rx/t-rx (MULTILIB_MATCHES): Don't handle uppercase -mcpu=
	argument.

From-SVN: r171932