[Mosaic TPU] Emulate converting x16 vector to mask if mask packing is…

… supported.

PiperOrigin-RevId: 716395352

tests/pallas/tpu_ops_test.py

@@ -271,15 +271,13 @@ def body(x_ref, y_ref):
     expected = expected.at[...].set(jnp.where(get_mask(x), 0.0, -1.0))
     np.testing.assert_array_equal(result, expected)
 
-  @parameterized.product(dtype=[jnp.float32, jnp.bfloat16, jnp.int8])
+  @parameterized.product(dtype=[jnp.float32, jnp.bfloat16, jnp.int16, jnp.int8])
   def test_cast_vector_to_mask(self, dtype):
+    if not jtu.if_cloud_tpu_at_least(2025, 1, 22):
+      self.skipTest("Requires libtpu built after 2025-01-22")
     shape = (128, 128)
     bitwidth = pallas_utils.dtype_bitwidth(dtype)
-    if (
-        (jtu.get_tpu_version() > 5 and bitwidth < 8)
-        or (jtu.get_tpu_version() == 5 and bitwidth not in (8, 32))
-        or (jtu.get_tpu_version() < 5 and bitwidth < 32)
-    ):
+    if jtu.get_tpu_version() < 5 and bitwidth < 32:
       self.skipTest(
           f"Not implemented: cast vector to mask with bitwidth == {bitwidth}"
       )