Basic optimizations for extflonums.
Add missing forms to TR docs.
More extflonum optimizations.
Tests for extflonum optimizations.
Export the ExtFlVector type.
Add extflvector optimizations.
Fix extflonum tests for line numbers.
Typo.
Be more conservative when reporing potentially exact arithmetic.
Optimize expt on floats.
Add -l flag to `raco test`.

Behaves similarly to `-l` for plain `racket`.
Up timeout for `tests/racket/link`.
Add remaining racket/list functions to TR base-env
Fix inference for dotted and starred arr types.
get-filename might return #f; check for that properly
adjust language test for new letrec semantics
Add pointer to the `syntax/modresolve` docs.
Add missing forms to TR docs.
Avoid precision problems in TR tests.
Fix Plot for new undefined behavior: #<undefined> is not a truth value

This is a nice example of why having #<undefined> as a language value is
generally a bad idea. Because in Scheme/Racket, everything that isn't
`refresh?` argument entirely - it was as if its value was always #t. Any
GUI change that was not meant to cause a refresh caused one anyway: a
silent performance error.