aarch64: Add support for SVE ADDPT, SUBPT, MADPT, MLAPT instructions

aarch64: Add support for SVE ADDPT, SUBPT, MADPT, MLAPT instructions

The following instructions are added in this patch:

- ADDPT (predicated): Add checked pointer vectors (predicated).
- ADDPT (unpredicated): Add checked pointer vectors (unpredicated).
- SUBPT (predicated): Subtract checked pointer vectors (predicated).
- SUBPT (unpredicated): Subtract checked pointer vectors (unpredicated).
- MADPT: Multiply-add checked pointer vectors, writing multiplicand
- MLAPT: Multiply-add checked pointer vectors, writing addend

These instructions are part of Checked Pointer Arithmetic extension
and are enabled when both CPA and SVE are enabled. To achieve this,
both flag "+sve" and "+cpa" should be active.

This patch adds assembler and disassembler support for these instructions
with relevant checks. Tests are included as well.

Regression tested on the aarch64-none-linux-gnu target and no regressions
have been found.