tests/extmod: Add test to compare time_ns with time.

They should be close together.

Signed-off-by: Damien George <damien@micropython.org>

tests/extmod/time_time_ns.py

@@ -22,3 +22,10 @@ if 2000000 < t1 - t0 < 50000000:
     print(True)
 else:
     print(t0, t1, t1 - t0)
+
+# Check that time.time() and time.time_ns() are within a second of each other.
+# Note that time.time() may return an int or float.
+for _ in range(10):
+    t_s, t_ns = time.time(), time.time_ns()
+    print(abs(t_s * 1_000 - t_ns // 1_000_000) <= 1_000)
+    time.sleep_us(100_000)

tests/extmod/time_time_ns.py.exp

@@ -1,2 +1,12 @@
 True
 True
+True
+True
+True
+True
+True
+True
+True
+True
+True
+True