Use GlobalRdrEnv
Try to implement NT as a newtype (but doesnt seem to work)
Revert "Try to implement NT as a newtype (but doesnt seem to work)"

This reverts commit 132b5e6bdabe4f358952f0b1c2cdeb1ac26643d8.
Simplify construction of CoreSyn
Further ease constructing NT lambdas
More general deriveThisNT
Lookup nttc “properly”
Extract error messages
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