This adds the noyywrap option so flex doesn't wait for more input once
we reached EOF. This also adds the nounput and noinput options to fix
compilation warnings.
We can now run the test as expected.
D lang compilers have an option -release (or similar) which turns off
asserts, contracts, and other runtime type checking. This patch wires
that up to the b_ndebug flag.
Fixes#7082