/* Start the user process by simulating a return from an
interrupt, implemented by intr_exit (in
- threads/intr-stubs.pl). Because intr_exit takes all of its
+ threads/intr-stubs.S). Because intr_exit takes all of its
arguments on the stack in the form of a `struct intr_frame',
we just point the stack pointer (%esp) to our stack frame
and jump to it. */