message: XFAIL TestRegisterVariables on gcc-4.8-x86_64
  I have previously enabled this test for this configuration. However, it turns
  out it only passes for gcc-4.9.
diff: @@ -101,6 +101,8 @@ class RegisterVariableTestCase(TestBase):
  @expectedFailureAll(compiler="clang", compiler_version=['<', '3.5'])
  @expectedFailureAll(compiler="gcc", compiler_version=[
  '>=', '4.8.2'], archs=["i386"])
  + @expectedFailureAll(compiler="gcc", compiler_version=[
  + '<', '4.9'], archs=["x86_64"])
  def test_and_run_command(self):
  """Test expressions on register values."""
  