[perl #129894] 1**NaN is 1, but any numeric operation with NaN should be NaN (say 1**NaN)

[Zoffix Znet via RT]

More, at nqp level:

<Zoffix> m: use nqp; dd nqp::pow_n(NaN, 0e0)
<camelia> rakudo-moar 2b5226: OUTPUT«1e0␤»
<Zoffix> m: use nqp; dd nqp::pow_n(1e0, NaN)
<camelia> rakudo-moar 2b5226: OUTPUT«1e0␤»