PR target/33049
	* config/avr/avr.md (extzv): New expander.
	(*extzv): New insn.
	(*extzv.qihi1, *extzv.qihi2): New insn-and-split.
	* config/avr/constraints.md (C04): New constraint.
	* doc/md.texi (Machine Constraints): Document it.

From-SVN: r175269