texmath-0.13.1.2: test/writer/tex/msup-02.test

<<< native
[ ESuper
    (EGrouped [ EPhantom (EIdentifier "fail") , EIdentifier "k" ])
    (ENumber "2")
, ESymbol Rel "="
, ESuper (EIdentifier "k") (ENumber "2")
]
>>> tex
{\phantom{fail}k}^{2} = k^{2}