Small changes to compile flags.
Small changes to compile flags.

* ghc-prim is available since 6.10, was part of base before
* -fregs-graph is activated by -O2 since ghc 7.0 and had
  performance issues before that. Reference: ticket #2790.

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