RESTART and TAGBODY

[Guy.Steele at CMU-10A]

Yes, indeed, I'm the spazzer to blame for that form that RESTART takes
in the sample interpreter, and it did happen by improper copying of the code
for RETURN.  Sigh.  I made it into RESTART and RESTART-FROM to parallel
RETURN and RETURN-FROM, but there seems to be universal opposition to this,
so I'll rename RESTART-FROM => RESTART if it gets kept.

As for TAGBODY versus PROGBODY, it seemed to me that the most important
characteristic of it was not that it is used to implement PROG (which
is the oldest but by no means most important construct to have such a body),
but rather that it bore tags; that is, I chose a name that described it
intrinsically rather than extrinsically.  I'm not passionate about this.
--Guy