decomp: eye (#778)

* decomp: `eye` close just need a pile of casts for the rendering code

* stash

* decomp: `eye` mostly cleaned up, xmm reg issue with `pextlb`

* waitin

* update ref tests and gsrc

* update reference tests

test/decompiler/reference/engine/target/sidekick_REF.gc

@@ -207,7 +207,7 @@
         (merc-blend-shape self)
         )
     (if (logtest? (-> self skel status) 384)
-        (merc-eye-anim self)
+        (merc-eye-anim (the-as manipy self))
         )
     (none)
     )