- Update the amd64 kernel support to recognize mchk_calltrap as a trapframe generator.
- Remove some unneeded headers from fbsd-kld.c.
- Various fixes to get stack traces working for aarch64 kernels:
- Map the LR register from the PCB to PC instead of LR.
- Skip the PC register from the PCB as it isn't initialized to anything.
- Correct the register cache map for the PCB. The old one had the offsets of pcb_sp and pcb_pc reversed.
- Don't map all of the saved general purpose registers in a trapframe to X1 rather than X0 .. X29.
- Use correct name for el0 trapframe entry points.
- Actually verified stack traces from kgdb on my rpi this time.