arm: Auto-vectorization for MVE: vbic

arm: Auto-vectorization for MVE: vbic

This patch enables MVE vbic instructions for auto-vectorization.  MVE
vbicq insns in mve.md are modified to use 'and not' instead of unspec
expression.

2020-12-11  Christophe Lyon  <christophe.lyon@linaro.org>

	gcc/
	* config/arm/iterators.md (supf): Remove VBICQ_S and VBICQ_U.
	(VBICQ): Remove.
	* config/arm/mve.md (mve_vbicq_u<mode>): New entry for vbic
	instruction using expression and not.
	(mve_vbicq_s<mode>): New expander.
	(mve_vbicq_f<mode>): Replace use of unspec by 'and not'.
	* config/arm/unspecs.md (VBICQ_S, VBICQ_U, VBICQ_F): Remove.

	gcc/testsuite/
	* gcc.target/arm/simd/mve-vbic.c: Add tests for vbic.