* src/fatest.c: make testable with failmalloc
* src/fatest.c: make testable with failmalloc

  - when FAILMALLOC_INTERVAL is set, report success, no matter
    how many tests failed (presumably because of memory starvation)
  - abort with die_oom() if crucial internal checks can't be performed
    because of allocation failures

hercules-team/augeas-do-not-use,mlichvar/augeas,MikaelSmith/augeas,domcleal/augeas,mchf/augeas,GeoffWilliams/augeas,pevalme/augeas,hercules-team/augeas-do-not-use,jtopjian/augeas,hercules-team/augeas,dafugg/augeas,mlichvar/augeas,jasperla/augeas,manandbytes/augeas,manandbytes/augeas,jjlin/augeas,kumy/augeas,ptoscano/augeas,mlichvar/augeas,hercules-team/augeas-do-not-use,kunkku/augeas,kunkku/augeas,raphink/augeas,ptoscano/augeas,kumy/augeas,kunkku/augeas,mchf/augeas,jtopjian/augeas,lutter/augeas,dafugg/augeas,domcleal/augeas,domcleal/augeas,jasperla/augeas,hercules-team/augeas,pevalme/augeas,GeoffWilliams/augeas,jjlin/augeas,jjlin/augeas,dafugg/augeas,lutter/augeas,pevalme/augeas,raphink/augeas,ptoscano/augeas,MikaelSmith/augeas,lutter/augeas,kumy/augeas,kumy/augeas