[PATCH][gdb] Fix hang after ext sigkill

[Simon Marchi]

On 2020-03-25 6:29 a.m., Tom de Vries wrote:
> Here's the updated patch.

Thanks.  Some comments about the test:

- Please add a comment at the top to describe briefly what this is testing.
- Please replace the infinite loops with bounded ones (e.g. for (i = 0; i < 300; i++)),
  so that the test program eventually exits if something goes wrong and it is allowed to run
  freely.

Simon