Generate "Prelude" of standard C types

[edsko]

In the repository there is a file standard_headers.h which imports all of the C standard library. We also have a skeleton implementation of some code (bootstrapPrelude) that trawls through these definitions; currently this is only being used to check if the macro parser is failing to parse some macros that we should be parsing (just to have a source of examples). We should extend this to make a list of all standard types in the standard library, and ensure that for all of these standard C types we have a well-defined translation to standard Haskell types (either from base or from hs-bindgen-patterns).