QEMU gdbstub should add memtag support for aarch64 MTE
GDB 11 has just been released, and the release notes include this item:
- New "qMemTags" and "QMemTags" remote protocol packets (associated with Memory Tagging).
We should implement support for these packets in our gdbstub so that gdb's AArch64 MTE support can read and write memory tags.