Function crossMapP for fixing desugaring of comprehensions
Function crossMapP for fixing desugaring of comprehensions

Merge into 6.6 branch.

iu-parfunc/containers,Zigazou/containers,iu-parfunc/containers,shockkolate/containers,shockkolate/containers,ekmett/containers,Zigazou/containers,iu-parfunc/containers,shockkolate/containers,hvr/containers,hvr/containers,Zigazou/containers,hvr/containers,ekmett/containers,meiersi/psqueues-old,ekmett/containers