test that t1-t0 > 100 ULP's

Author: jpbrodrick89

diffrax/_integrate.py

@@ -303,6 +303,11 @@ def loop(
     t1_clip_floor = t1
     for _ in range(100):
         t1_clip_floor = eqxi.prevbefore(t1_clip_floor)
+    if jnp.sign(t1_clip_floor - t0) != jnp.sign(t1 - t0):
+        raise ValueError(
+            "t0 and t1 are within 100 units of least precision "
+            "implying a high risk of floating point error. Aborting."
+        )
 
     if saveat.dense:
         dense_ts = init_state.dense_ts