Break loop in interface typechecking (fixes Trac #8002)
Tidy up the segmentation of mdo expressions

When we changed 'rec' to *not* do segmentation of any kind,
I did it by meddling with the inner loop of grab in glomSegments.
But that is really hard to understand!

This patch lifts the test out to the top where is is clear.
Make sure that Pretty.text is inlined in stage 0,
so that RULE text/str gets a chance to fire (Trac #7995).

And make sure that Outputable.text is inlined, so that the underlying
Pretty.text rule can fire.

The thing is that literal strings only turn into unpackCString#
in phase 1.
Allow associated types as sub-names in an import list (Trac #8011)
White space and ordering only