Let isinstance() work with non-type metaclasses

src/runtime/objmodel.cpp

@@ -1913,9 +1913,9 @@ extern "C" bool isinstance(Box* obj, Box* cls, int64_t flags) {
     }
 
     if (!false_on_noncls) {
-        assert(cls->cls == type_cls);
+        assert(isSubclass(cls->cls, type_cls));
     } else {
-        if (cls->cls != type_cls)
+        if (!isSubclass(cls->cls, type_cls))
             return false;
     }
 

test/tests/metaclasses.py

@@ -26,6 +26,9 @@ class C(object):
     __metaclass__ = M
 
 print "Made C", type(C)
+print isinstance(C, M)
+print isinstance(C, type)
+print isinstance(C, int)
 
 def f(*args):
     print "f()", args[:2]