rs6000: Use set_attr_alternative in some places

rs6000: Use set_attr_alternative in some places

Some code is much neater if it uses set_attr_alternative than if it
does everything by hand.  Change some patterns to use this shorthand.

	* config/rs6000/rs6000.md (*movcc_internal1): Use set_attr_alternative.
	(*call_indirect_nonlocal_sysv<mode>): Ditto.
	(*call_value_indirect_nonlocal_sysv<mode>): Ditto.
	(*sibcall_nonlocal_sysv<mode>): Ditto.
	(*sibcall_value_nonlocal_sysv<mode>): Ditto.
	(<bd>_<mode>): Ditto.
	(<bd>tf_<mode>): Ditto.

From-SVN: r264588