TITLE: double fault in x86_df_handler

ZIRCON KERNEL PANIC
vector 8
double fault, halting
 CS:                0x33 RIP:     0x6b8144262960 EFL:            0x10202 CR2: 0xfffffffffffffff8
 RAX:                  0 RBX:                  0 RCX:                  0 RDX:                  0
 RSI:                  0 RDI:                  0 RBP:                  0 RSP:                  0
  R8:                  0  R9:                  0 R10:                  0 R11:                  0
 R12:                  0 R13:                  0 R14:                  0 R15:                  0
errc:                  0
platform_halt suggested_action 0 reason 9
bt#00: 0x00105972 platform_halt platform/pc/power.cpp:122
bt#01: 0x00108425 exception_die arch/x86/faults.cpp:97
bt#02: [ inline ] x86_df_handler arch/x86/faults.cpp:175
bt#02: [ inline ] handle_exception_types arch/x86/faults.cpp:349
bt#02: 0x00108d63 x86_exception_handler arch/x86/faults.cpp:455
bt#03: 0x0011599e interrupt_common arch/x86/exceptions.S:127
bt#04: end
