compiler: load imports and enforce package exports

test/wcc/data/r787_xmod_variant_foreign_qualifier/case.ww

@@ -1,5 +1,8 @@
-//ww:error c "is not a variant of" ww "ambiguous without nominal layout"
-// migrated from test/wcc/787_xmod_variant_match.c: a same-leaf variant from a DIFFERENT module is NOT a variant of the scrutinee — guards #13 against bare leaf-strip false-accept.
+//ww:error c "is not a variant of" ww "not a variant of scrutinee"
+// migrated from test/wcc/787_xmod_variant_match.c: a same-leaf variant from a
+// DIFFERENT module is NOT a variant of the scrutinee — guards #13 against bare
+// leaf-strip false-accept. Both checkers now resolve the direct qualifier before
+// codegen and reject at the case boundary.
 package pkg;
 export type a = !void;
 export type b = !void;