message: Report the exact stop location when "check_function_name" match fails.
  Also always check that our "step" operations are completing and not getting interrupted.
  We are seeing this test fail intermittantly on Linux, so I'm adding a little more
  diagnostic to the fail to help see what actually went wrong.
diff: @@ -48,8 +48,14 @@ class TestSwiftStepping(lldbtest.TestBase):
  "settings set "
  "target.process.thread.step-avoid-libraries {}".format(lib_name))
  + def correct_stop_reason(self, thread):
  + # We are always just stepping, so that should be the thread stop reason:
  + stop_reason = thread.GetStopReason()
  + self.assertEqual(stop_reason, lldb.eStopReasonPlanComplete)
  +
  def hit_correct_line(self, thread, pattern, fail_if_wrong=True):
  # print "Check if we got to: ", pattern
  + self.correct_stop_reason(thread)
  target_line = lldbtest.line_number(self.main_source, pattern)
  self.assertTrue(
  target_line != 0,
  @@ -65,10 +71,17 @@ class TestSwiftStepping(lldbtest.TestBase):
  def hit_correct_function(self, thread, pattern):
  # print "Check if we got to: ", pattern
  + self.correct_stop_reason(thread)
  name = thread.frames[0].GetFunctionName()
  + line_entry = thread.frames[0].GetLineEntry()
  + desc = lldb.SBStream()
  + if line_entry.IsValid():
  + line_entry.GetDescription(desc)
  + else:
  + desc.Print(name)
  self.assertTrue(
  pattern in name,
  - "Got to '%s' not the expected function '%s'." % (name, pattern))
  + "Got to '%s' not the expected function '%s'." % (desc.GetData(), pattern))
  def do_test(self):
  """Tests that we can step reliably in swift code."""
  