This is a collection of independant and mostly trivial cleanups.
I don't attach the combined patch as it is the concatenation of the separate
patches.

Patch 07: Useless coarray code removal.
Patch 08: Remove redundant condition.
Patch 09: Assertify condition.
Patch 10: Use array dimensions instead of loop dimensions.
Patch 11: Skip temporary arrays for loopspec choice.
Patch 12: Stop loop before end marker.