Be more careful when testing NaNs (and fix a failing test on Android).

[jpellegrini]

(* 0+1i +inf.0) can be -nan.0+inf.0i (on Linux/amd64 for example) and also +nan.0+inf.0i (on Android, for example). So we don't test the sign of the NaN.

[jpellegrini]

(This morning I realized that this test was failing on Android)

[jpellegrini]

@egallesio I think this is not necessary anymore, since you have committed a much better fix! :)

By the way, all tests pass on Android now. :smiley:

[egallesio]

Oops. Forgot to tell you that it is corrected now, but you have seen it :smiley: