allow expand on cross-phase-persistent modules

Previoulsy, `expand` mode explicitly disallowed cross-phase declaration
in commit 2e652fc2b3. I'm not sure why, and that commit has no test
case that fails when the restriction is removed, so my best guess is
that it was a debugging strategy that I forgot to undo.

pkgs/racket-pkgs/racket-test/tests/racket/cross-phase.rkt

@@ -108,5 +108,13 @@
                'ok))
       (error 'cross-phase "redeclaration should have been disallowed"))))
 
+;; Check that `expand` allows cross-phase modules:
+(parameterize ([current-namespace (make-base-namespace)])
+  (void
+   (expand (datum->syntax
+            #f
+            '(module m '#%kernel
+               (#%declare #:cross-phase-persistent))))))
+
 (displayln "All tests passed.")
 

racket/src/racket/src/module.c

@@ -7390,7 +7390,7 @@ static Scheme_Object *do_module(Scheme_Object *form, Scheme_Comp_Env *env,
   m->tt_requires = scheme_null;
   m->dt_requires = scheme_null;
 
-  if (iim && iim->phaseless && rec[drec].comp)
+  if (iim && iim->phaseless)
     m->phaseless = scheme_true;
 
   if (iidx) {