aarch64: Add support for the id_aa64isar3_el1 system register

Hi,

[PATCH][Binutils] aarch64: Add support for the id_aa64isar3_el1 system register

AArch64 defines a read-only system register called id_aa64isar3_el1.
This patch also adds relevant tests.

Regression tested on the aarch64-none-elf and aarch64-none-linux-gnu targets
and no regressions was found.

Is this Ok for trunk? I do not have commit rights, if OK, can someone commit on my behalf?

Thanks,
Yury Khrustalev

From e42c835e8f2ee81150f498675f2faf108bbe79f8 Mon Sep 17 00:00:00 2001
From: Yury Khrustalev <yury.khrustalev@arm.com>
Date: Tue, 6 Feb 2024 11:05:39 +0000
Subject: [PATCH] [PATCH][Binutils] aarch64: Add support for the
 id_aa64isar3_el1 system register

AArch64 defines a read-only system register called id_aa64isar3_el1.
This patch also adds relevant tests.

Regression tested on the aarch64-none-elf and aarch64-none-linux-gnu targets
and no regressions was found.