aarch64: Fix bogus cnot optimisation [PR114603]

aarch64: Fix bogus cnot optimisation [PR114603]

aarch64-sve.md had a pattern that combined:

	cmpeq	pb.T, pa/z, zc.T, #0
	mov	zd.T, pb/z, #1

into:

	cnot	zd.T, pa/m, zc.T

But this is only valid if pa.T is a ptrue.  In other cases, the
original would set inactive elements of zd.T to 0, whereas the
combined form would copy elements from zc.T.

gcc/
	PR target/114603
	* config/aarch64/aarch64-sve.md (@aarch64_pred_cnot<mode>): Replace
	with...
	(@aarch64_ptrue_cnot<mode>): ...this, requiring operand 1 to be
	a ptrue.
	(*cnot<mode>): Require operand 1 to be a ptrue.
	* config/aarch64/aarch64-sve-builtins-base.cc (svcnot_impl::expand):
	Use aarch64_ptrue_cnot<mode> for _x operations that are predicated
	with a ptrue.  Represent other _x operations as fully-defined _m
	operations.

gcc/testsuite/
	PR target/114603
	* gcc.target/aarch64/sve/acle/general/cnot_1.c: New test.