* c-common.c (registered_builtin_types): New static.
	(c_common_type_for_mode): Consult registered_builtin_types.
	(c_register_builtin_type): Add type to registered_builtin_types.
	* optabs.c (init_floating_libfuncs): Initialize libfuncs for
	all MODE_FLOAT modes, not just the ones corresponding to
	float_type_node, double_type_node, and long_double_type_node.

From-SVN: r72711