1.0.45.13: physenvanal: Treat all functions without XEPs as being D-X.

1.0.45.13: physenvanal: Treat all functions without XEPs as being D-X.

  * In order for a function to be returned or passed as a parameter,
it must have an XEP.

  * Functions without XEPs, therefore, can only be called directly
from within their lexical scope.  They are, therefore,
dynamic-extent.

  * But wait, you say, they could be called from a closure that is
not dynamic-extent, which clearly shows such an analysis to be false.

  * It turns out that this doesn't matter, because the non-dynamic-
extent closure also has to close over the variables passed to the
supposedly-dynamic-extent closure, and that will cause explicit
value-cells to be allocated anyway.

  * So, it's a bit of an abuse to say that the functions have dynamic
extent, but it does no harm (and quite a bit of good) to treat them
as if they do.