prepare for decompiling display (#359)

* prepare for decompiling display

Needs some work on the decompiler (mostly bitfield stuff) before a more proper decomp can be done

* make `(profile-bar draw)`, `set-display-gs-state-offset` and `set-display-env` decompile

decompiler should now support unsigned divide

* fill in some dma-h types

* Fill in a few VIF bitfields + other minor fixes

* Update all-types.gc

* Fix stupid mistake in `vif-mask`

* update dma-h reference

* this uint32 is actually a `vif-tag` (oops)

test/decompiler/reference/all_forward_declarations.gc

@@ -121,6 +121,9 @@
 (defmacro .sync.l ()
   `(none))
 
+;; timer-h
+(declare-type dma-buffer basic)
+
 ;; display-h
 (deftype display-env (structure)
   ((pmode   uint64  :offset-assert 0)