/*
=for apidoc mro_get_linear_isa_dfs
-Returns the Depth-First Search linearization of @ISA
+Returns the Depth-First Search linearization of C<@ISA>
the given stash. The return value is a read-only AV*.
C<level> should be 0 (it is used internally in this
function's recursion).
=for apidoc mro_isa_changed_in
Takes the necessary steps (cache invalidations, mostly)
-when the @ISA of the given package has changed. Invoked
+when the C<@ISA> of the given package has changed. Invoked
by the C<setisa> magic, should not need to invoke directly.
=cut