aarch64: Fold aarch64_sve_op_count into aarch64_vec_op_count

aarch64: Fold aarch64_sve_op_count into aarch64_vec_op_count

Later patches make aarch64 use the new vector hooks.  We then
only need to track one set of ops for each aarch64_vector_costs
structure.  This in turn means that it's more convenient to merge
aarch64_sve_op_count and aarch64_vec_op_count.

The patch also adds issue info and vec flags to aarch64_vec_op_count,
so that the structure is more self-descriptive.  This simplifies some
things later.

gcc/
	* config/aarch64/aarch64.c (aarch64_sve_op_count): Fold into...
	(aarch64_vec_op_count): ...this.  Add a constructor.
	(aarch64_vec_op_count::vec_flags): New function.
	(aarch64_vec_op_count::base_issue_info): Likewise.
	(aarch64_vec_op_count::simd_issue_info): Likewise.
	(aarch64_vec_op_count::sve_issue_info): Likewise.
	(aarch64_vec_op_count::m_issue_info): New member variable.
	(aarch64_vec_op_count::m_vec_flags): Likewise.
	(aarch64_vector_costs): Add a constructor.
	(aarch64_vector_costs::m_sve_ops): Change type to aarch64_vec_op_count.
	(aarch64_vector_costs::aarch64_vector_costs): New function.
	Initialize m_scalar_ops, m_advsimd_ops and m_sve_ops.
	(aarch64_vector_costs::count_ops): Remove vec_flags and
	issue_info parameters, using the new aarch64_vec_op_count
	functions instead.
	(aarch64_vector_costs::add_stmt_cost): Update call accordingly.
	(aarch64_sve_op_count::dump): Fold into...
	(aarch64_vec_op_count::dump): ..here.