* config/h8300/h8300.c (h8300_init_once): Default to
-fstrict_volatile_bitfields.

* config/sh/sh.c (sh_override_options): Default to
-fstrict_volatile_bitfields.

* config/rx/rx.c (rx_option_override): New.

* config/m32c/m32c.c (m32c_override_options): Default to
-fstrict_volatile_bitfields.

From-SVN: r162149