HEAD doesn't build: No rule to make target 'TcTypeNats.hs'

[David Luposchainsky]

It seems the recent commit 1f77a53 [1] introduced changes the build
system isn't prepared for. ad15c2b builds just fine, but the mentioned
commit introduces a make error,

> make[1]: *** No rule to make target 
> `compiler/stage1/build/TcTypeNats.hs', needed by 
> `compiler/stage1/build/.depend-v.haskell'.  Stop.

Since that's a rather large patch, I'm not sure how to fix it (or
whether it really just is the build system that fails and not more).


[1]:
https://github.com/ghc/ghc/commit/1f77a5341cbd6649a6bc2af868002728cd79b9d7