Note that `ans-report.fs' just checks which words are used, not whether
they are used in an ANS Forth conforming way!
Some words are defined in several wordsets in the
standard. `ans-report.fs' reports them for only one of the
wordsets, and not necessarily the one you expect. It depends on usage
which wordset is the right one to specify. E.g., if you only use the
compilation semantics of
S", it is a Core word; if you also use
its interpretation semantics, it is a File word.