[valid-invariant.html]
  [WebGL test #0: [unexpected link status\] vertex shader with invariant varying and fragment shader with variant varying must succeed]
    expected: FAIL

  [WebGL test #1: [unexpected link status\] vertex shader with invariant (global setting) varying and fragment shader with variant varying must succeed]
    expected: FAIL

  [WebGL test #2: [unexpected link status\] vertex shader with invariant (separately set) varying and fragment shader with variant varying must succeed]
    expected: FAIL