MINOR: debug: report the task handler's pointer relative to main

Often in crash dumps we see unknown function pointers. Let's display
them relative to main, that helps quite a lot figure the function
from an executable, for example:

  (gdb) x/a main+645360
  0x4c56a0 <h1_timeout_task>:     0x2e6666666666feeb

This could be backported to 2.0.

(cherry picked from commit 516853f1cc144bfe5d0010fc12d5f385341e67ab)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 68eb0aa9e688024b4842022fc7c73984d0806d98)
Signed-off-by: Willy Tarreau <w@1wt.eu>
1 file changed