Refs Tokutek/ft-index#28 Add function to attach gdb to the running process and extract information.
(cherry picked from commit fa39b2a3514e26f1b94b5a905753c771bb3244e6)
Refs Tokutek/ft-index#28  Fix compile failure on systems that don't support PR_SET_PTRACER
(cherry picked from commit 1518fb179c14afe0ad5b7a1b4f9205aa328a7715)
Refs Tokutek/ft-index#28  Fix compile failure
(cherry picked from commit 7148e0b96b12c3fccf5ea17e15e5a175ebcdac65)
Refs Tokutek/ft-index#28  Fix compile failure on machines without prctl
(cherry picked from commit e32777081cc77fa8de51b88c928e6826615072ef)
Refs Tokutek/ft-index#28  Use prctl (on any linux) even if it is too old for PR_SET_PTRACER.
Ignore any error caused by this
(cherry picked from commit 3ac10021afbef01d27ce993cdd6030052007c191)