also occupies a single slot. There's no need for any special handling
of Quads. While here, remove the silly make_quad() function. We have
the 2 longs on 32-bit machines already lined up in the argument array,
so we can fetch the Quad with a simple cast.
Before:
lseek(1,0x123456789,0xd0d0d0d0d0d0d0d0) = 4886718345 (0x123456789)
After:
lseek(1,0x123456789,SEEK_SET) = 4886718345 (0x123456789)