Correctly handle inline fields that aren't present in the parent struct (i.e. because we're reading an older version of the struct that lacked those fields).

ignore /compiler/dist from cabal install

Improve unions.  Members of a union are now scoped within the union, although they share ordinal space with the parent struct.

Get rid of redundant ErrorReporter that goes in ReaderOptions.  Registering an ExceptionCallback is a better approach.