Compiling Messages.hs is slow

[HairyDude]

Loading Messages.hs in GHCi is quick enough, but compiling it is very slow, even with optimizations off. With -O2 my computer runs out of memory. This is probably a consequence of these GHC bugs:

• Compiling DynFlags is jolly slow
• Regression in optimisation time of functions with many patterns (6.12 to 7.4)?

In particular the second, since ScriptMessage is a record type with many constructors (one for each message, of which there are currently >300), and the ToMessage(?) instance is just a function with a huge number of patterns.

[HairyDude]

The untemplate branch works around this issue by replacing the mkMessage splice in Messages.hs with its expansion. It's much easier to add messages using mkMessage so I'd like to go back to doing that, but that will have to wait till these GHC bugs are fixed.