Running without a video device results in a crash of app_server

[kallisti5]

KERN: vm_page_fault: vm_soft_fault returned error 'Bad address' on fault at 0x0, ip 0x9ca8269747, write 0, user 1, exec 0, thread 0x153
KERN: debug_server: Thread 339 entered the debugger: Segment violation
KERN: stack trace, current PC 0x9ca8269747  </boot/system/servers/app_server> _ZNK11HWInterface12_CopyToFrontEPhjiiii + 0x207:
KERN:   (0x7f9c42508c90)  0x9ca8269bc2  </boot/system/servers/app_server> _ZN11HWInterface16_CopyBackToFrontER7BRegion + 0x92
KERN:   (0x7f9c42508cf0)  0x9ca824e219  </boot/system/servers/app_server> _ZN21AccelerantHWInterface16_CopyBackToFrontER7BRegion + 0xd9
KERN:   (0x7f9c42508d50)  0x9ca826b6f7  </boot/system/servers/app_server> _ZN11HWInterface15CopyBackToFrontERK5BRect + 0x187
KERN:   (0x7f9c42508df0)  0x9ca826912b  </boot/system/servers/app_server> _ZN11HWInterface16InvalidateRegionERK7BRegion + 0x5b
KERN:   (0x7f9c42508e50)  0x9ca8261432  </boot/system/servers/app_server> _ZN13DrawingEngine10FillRegionER7BRegionRK9rgb_color + 0x172
KERN:   (0x7f9c42508f10)  0x9ca81f6165  </boot/system/servers/app_server> _ZN7Desktop14_SetBackgroundER7BRegion + 0xa5
KERN:   (0x7f9c42508f80)  0x9ca81fa224  </boot/system/servers/app_server> _ZN7Desktop4InitEv + 0x354
KERN:   (0x7f9c42509040)  0x9ca81edf9f  </boot/system/servers/app_server> _ZN9AppServer14_CreateDesktopEjPKc + 0x4f
KERN:   (0x7f9c42509090)  0x9ca81ee25d  </boot/system/servers/app_server> _ZN9AppServer15MessageReceivedEP8BMessage + 0x14d
KERN:   (0x7f9c42509140)  0x1ff4a201b54  </boot/system/lib/libbe.so> _ZN7BLooper11task_looperEv + 0x284
KERN:   (0x7f9c42509190)  0x1ff4a1f6ad1  </boot/system/lib/libbe.so> _ZN12BApplication3RunEv + 0x21
KERN:   (0x7f9c425091b0)  0x9ca81eccf2  </boot/system/servers/app_server> main + 0x52
KERN:   (0x7f9c425091e0)  0x9ca81ed76f  </boot/system/servers/app_server> _start + 0x3f
KERN:   (0x7f9c42509210)  0x2157be3eae5  </boot/system/runtime_loader> runtime_loader + 0x105

Running on GCE under EFI. There's no video device so the app_server just crashes with the above. However, sshd is running and the system can be used via a terminal.

We should likely guard the crash above with a "No video device found" or something?