arm: [MVE intrinsics] factorize vqrshrunb vqrshrunt vqshrunb vqshrunt

arm: [MVE intrinsics] factorize vqrshrunb vqrshrunt vqshrunb vqshrunt

Factorize vqrshrunb, vqrshrunt, vqshrunb, vqshrunt so that they use
existing patterns.

2022-09-08  Christophe Lyon  <christophe.lyon@arm.com>

	gcc/
	* config/arm/iterators.md (MVE_SHRN_N): Add VQRSHRUNBQ,
	VQRSHRUNTQ, VQSHRUNBQ, VQSHRUNTQ.
	(MVE_SHRN_M_N): Likewise.
	(mve_insn): Add vqrshrunb, vqrshrunt, vqshrunb, vqshrunt.
	(isu): Add VQRSHRUNBQ, VQRSHRUNTQ, VQSHRUNBQ, VQSHRUNTQ.
	(supf): Likewise.
	* config/arm/mve.md (mve_vqrshrunbq_n_s<mode>): Remove.
	(mve_vqrshruntq_n_s<mode>): Remove.
	(mve_vqshrunbq_n_s<mode>): Remove.
	(mve_vqshruntq_n_s<mode>): Remove.
	(mve_vqrshrunbq_m_n_s<mode>): Remove.
	(mve_vqrshruntq_m_n_s<mode>): Remove.
	(mve_vqshrunbq_m_n_s<mode>): Remove.
	(mve_vqshruntq_m_n_s<mode>): Remove.