message: Clear caches on eager context reset.
  Clear the caches of the existing eager context before deleting it as some of these caches are cpp static (TFE_TensorHandleCache) and will therefore be inherited by future contexts with some out of date content which might lead to some segfaults.
diff: @@ -1637,6 +1637,7 @@ def _reset_context():
  global _context
  with _context_lock:
  if _context is not None:
  + _context._clear_caches()
  _context = None
  _create_context()
  pywrap_tfe.TFE_ClearScalarCache()
  