BaseFakeNumpyNamespace -> implement isnan

Author: kaushikcfd

arraycontext/fake_numpy.py

@@ -86,7 +86,7 @@ def _get_fake_numpy_linalg_namespace(self):
 
         # Miscellaneous
         "convolve", "clip", "sqrt", "cbrt", "square", "absolute", "abs", "fabs",
-        "sign", "heaviside", "maximum", "fmax", "nan_to_num",
+        "sign", "heaviside", "maximum", "fmax", "nan_to_num", "isnan",
 
         # FIXME:
         # "interp",

test/test_arraycontext.py

@@ -367,6 +367,7 @@ def assert_close_to_numpy_in_containers(actx, op, args):
             ("abs", 1, np.complex128),
             ("sum", 1, np.float64),
             ("sum", 1, np.complex64),
+            ("isnan", 1, np.float64),
             ])
 def test_array_context_np_workalike(actx_factory, sym_name, n_args, dtype):
     actx = actx_factory()