Why does lib:ghc depend on ghci for stage1?

[angerman]

Generally building a ghc for stage1 should be the minimal ghc we can build with the least bells and whistles, yet stage1 ghc seems to depend on ghci, and ghc-internal, and all kinds of other complicated libraries. We need to create a clear dependency graph of what ghc-bin depends on and see if we can cut this down (conditionally) in stage1.

ghc-bin should not need any dynamic features in stage1. It just needs to be able to compile haskell code. And produce a stage2 compiler that may be able to compile dynamic stuff. I think we should be rather adamant about stage1 NOT being TH capable, and as such keeping GHC TH free.

This might also eventually pave the way to build ghc stage1 with microhs.