rustc: Change fn_names and fn_ids to item_names and item_ids in trans, since we're soon to be storing tags in there too

rustc: Remove the premature optimization for nullary tag constructors, since it'll be no longer necessary once LLVM gets a unit type

Avoid segfault due to fallthrough in base case of incr_all_refcounts. We could use a typestate checker in rustc, any time now.

Check and translate 'as' cast-operator, lower target-specific types, reindent rustc.rs, enable uint test.

Switch module-internal calls (i.e. all user code) to fastcall. Still returning via explicit outptr. Activate glue works by accident.

Move phi-node generation into a helper that measures the liveness of each incoming edge. Factorial test now succeeds.