This register should be 64 bits in size, but the current code only saves
32 bits. This is due to an early assumption that tag_ctl would be 32 bits
in size.
gdb/ChangeLog:
2021-06-28 Luis Machado <luis.machado@linaro.org>
* aarch64-linux-tdep.c
(aarch64_linux_iterate_over_regset_sections): Update tag_ctl register
size.
* aarch64-linux-tdep.h (AARCH64_LINUX_SIZEOF_MTE_REGSET): Set to
8 and update comments.