* Fixed issue where bound vars were passed twice
* Fixed issue where enumeration tycons were processed twice
* Fixed mu type errors

NOTE: cg_loc doesn't do anything in getCallMethod anyway, so we
can leave it as `undefined`. This may change in later API versions.

Currently does not compile because ghc-simple cannot fetch DynFlags.
Oh well, we should probably move away from ghc-simple anyway since
post-lts-7.0 it has contradictory dependencies.

-> Removed ad-hoc stack
-> Removed SRT-related code, since they won't be present on the stack anyway
-> Streamlined info table representation (at the expense of alignment)

Currently Zebu throws an error, but I suspect this is due to
a bug in the underlying `mu-client-ghc-api` library.

-> Created module header stubs
-> Fixed type/API bugs

This is to make it work with global cells, which cannot be treated
as refs. Potentially this will influence performance since the GC
needs to figure out whether the thing being referenced is a heap
object etc. Yi assures me this doesn't apply to Zebu.

TODO: fix issues around top-level things being double-indirected
through the global cells.

This involved fixing a lot of the closure code, since it was
revealed that two closures may share an info table.

There's a lot to fix, but there's enough of a skeleton in place,
and code that is obviously wrong is marked with FIXME. This
branch is now ready to merge.

So far we are sketching out a skeleton for these functions that
type-checks with the new closure representation -- FIXME comments
point out where we e.g. write incorrect metadata to the closures.

The end goal for this branch is to have FromSTG compile. This will
involve fixing all static closures to use the new representation,
as well as incorporating type information into all bindings and
function calls.

Also we should fix mkClosure' to use the new
representation before merging.