Add some functions to the array_helpers exports

Author: asmeurer

array_api_tests/array_helpers.py

@@ -26,7 +26,8 @@
            'assert_positive_mathematical_sign', 'negative_mathematical_sign',
            'assert_negative_mathematical_sign', 'same_sign',
            'assert_same_sign', 'ndindex', 'promote_dtypes', 'float64',
-           'asarray']
+           'asarray', 'is_integer_dtype', 'is_float_dtype', 'dtype_ranges',
+           'full']
 
 def zero(shape, dtype):
     """