Final test, gdbstub, plugin and gitdm updates for 8.2 - fix duplicate register in arm xml - hide various duplicate system registers from gdbstub - add new gdb register test to the CI (skipping s390x/ppc64 for now) - introduce GDBFeatureBuilder - move plugin initialisation to after vCPU init completes - enable building TCG plugins on Windows platform - various gitdm updates - some mailmap fixes - disable testing for nios2 signals which have regressed