C utilities should be built by the provisioner

[rogerhub]

From a student:

When I tried running 'pintos run alarm-multiple' I got an error stating squish-pty couldn't be executed (cannot execute binary file: Exec format error). To fix this, I went into /home/vagrant/.bin and ran 'gcc squish-pty.c -o squish-pty'. I did this because the error message suggested that squish-pty had been compiled for a 64-bit arch. After this, 'pintos run alarm-multiple' worked fine and ran all the tests.

I just wanted to let the staff know about this in case the provisioner should be modified to build squish-pty from source during provisioning.