[Rd] complex NA's match(), etc: not back-compatible change proposal

[Suharto Anggono Suharto Anggono]

I am raising this again.

With
z <- complex(real = c(0,NaN,NaN), imaginary = c(NA,NA,0)) ,
results of
sapply(z, match, table = z)
and
match(z, z)
are different in R 3.4.0 alpha. I think they should be the same.

I suggest changing 'cequal' in unique.c such that a complex number that has both NA and NaN matches NA and doesn't match NaN, as such complex number is printed as NA.