Mainstream-aligns the Float surface: + - * / < <= > >= become
forall-quantified with codegen-dispatch on Int|Float (parallel to
today's == path), instead of the original draft's wort-style
fadd/flt/etc. Adds nan/inf/neg_inf as builtin constants and
is_nan : (Float) -> Bool. % stays Int-only (no fmod yet).
Iteration plan now flags iter 3 and iter 4 as widening passes
that must hold the no-Int-regression line.
Brummel
f7e2c3ee7a