message: Make TestStaticVariables XFAIL more specific
  The test fails because an older clang did not emit the required debug
  info (I am not sure when this got added, but clang-3.7 certainly did not
  work yet). The actual platform has nothing to do with this.
diff: @@ -60,10 +60,9 @@ class StaticVariableTestCase(TestBase):
  compiler=["gcc"],
  bugnumber="Compiler emits incomplete debug info")
  @expectedFailureAll(
  - oslist=['linux'])
  - @expectedFailureAll(
  - oslist=['freebsd'],
  - bugnumber='llvm.org/pr20550 failing on FreeBSD-11')
  + compiler=["clang"],
  + compiler_version=["<", "3.8"],
  + bugnumber='llvm.org/pr20550')
  @add_test_categories(['pyapi'])
  def test_with_python_api(self):
  """Test Python APIs on file and class static variables."""
  @@ -102,11 +101,11 @@ class StaticVariableTestCase(TestBase):
  if name == 'g_points':
  self.assertTrue(
  val.GetValueType() == lldb.eValueTypeVariableStatic)
  - self.assertTrue(val.GetNumChildren() == 2)
  + self.assertEqual(val.GetNumChildren(), 2)
  elif name == 'A::g_points':
  self.assertTrue(
  val.GetValueType() == lldb.eValueTypeVariableGlobal)
  - self.assertTrue(val.GetNumChildren() == 2)
  + self.assertEqual(val.GetNumChildren(), 2)
  child1 = val.GetChildAtIndex(1)
  self.DebugSBValue(child1)
  child1_x = child1.GetChildAtIndex(0)
  