two functions for everything

[David C. Plummer <DCP@QUABBIN.SCRC.Symbolics.COM>]

This is bogus folks.  All you need is two entrypoints: one which doesn't
check anything, and one which checks what it needs to.  They then join.
Safety 0 (at compile time) causes functions to call the the
don't-check-anything entrypoint, and safety > 0 causes functions to call
the one that checks.  Hell, you could have a different entrypoint for
each setting of safety.

We should be debating implementation issues less and debating what we
want the specification for a robust language to state.