forcing tail/sibling call optimization

[Robert Dewar]

<<IMHO we shouldn't encourage users to rely on gcc being able to optimize
tail calls.  It's a nice optimization, but if a program relies on it for
correctness, that program is broken.
>>

That is certainly true in C, but it makes C useless as a target for the
kind of translation being considered here, where the "optimization" is
a fundamental requirement. The discussion on the above subject line,
is all about creating a variant language that WOULD have the required
semantic characteristics.