glsl: has_transform_feedback_varyings can be incorrectly flagged on fragment shaders
dEQP-GLES3.functional.transform_feedback.basic_types.interleaved.lines.lowp_uint
exhibits this behavior
cc @tarceri
dEQP-GLES3.functional.transform_feedback.basic_types.interleaved.lines.lowp_uint
exhibits this behavior
cc @tarceri