issue MACRO-ENVIRONMENT-CREATOR, version 1

[Glenn S. Burke <gsb@ALDERAAN.SCRC.Symbolics.COM>]

You still need the ability to handle flet (i.e., shadow macro definitions).
While one could say that a definition with only a name does that, i.e.
(make-macro-environment '((flet-function-name-1) (flet-function-name-2))),
a syntax like this is not amenable to any future extension.