test: move simple/test-abort-fatal-error to pummel

Move it from simple/ to pummel/ because it can take an awful long to
run to completion:

    $ time out/x64.release/node test/simple/test-abort-fatal-error.js

    real    0m8.150s
    user    0m0.328s
    sys     0m0.054s

R=@chrisdickinson?