!6761 remove redundant check about IsInstance op

Merge pull request !6761 from liangzelang/fix_isinstance_op_bug

mindspore/ops/operations/array_ops.py

@@ -347,8 +347,6 @@ class IsInstance(PrimitiveWithInfer):
         sub_type_t = inst['dtype']
         type_v = type_['value']
 
-        if not isinstance(inst, type(mstype.tensor)):
-            validator.check_const_input("inst", inst['value'], self.name)
         validator.check_value_type("type_", type_v, [mstype.Type], self.name)
 
         if type_v == mstype.list_:

tests/ut/python/ops/test_array_ops_check.py

@@ -114,11 +114,6 @@ raise_set = [
         'desc_inputs': [mstype.number, None],
         'skip': ['backward']}),
 
-    # inst is var
-    ('IsInstance0', {
-        'block': (P.IsInstance(), {'exception': ValueError, 'error_keywords': ['IsInstance']}),
-        'desc_inputs': [5.0, mstype.number],
-        'skip': ['backward']}),
     # t is not mstype.Type
     ('IsInstance1', {
         'block': (IsInstanceNet(5.0), {'exception': TypeError, 'error_keywords': ['IsInstance']}),