[decomp] math-camera (#491)

* decompile math camera

* missing line

test/decompiler/reference/all_forward_declarations.gc

@@ -415,7 +415,7 @@
      (.mov upper-xmm ,upper)
      (.mov lower-xmm ,lower)
      (.pcpyld result upper-xmm lower-xmm)
-     result
+     (the uint result)
      )
   )
 
@@ -587,5 +587,4 @@
 (define-extern vector-rad<-vector-deg! (function vector vector none))
 (define-extern vector-rad<-vector-deg/2! (function vector vector int))
 
-; process-drawable
-(define-extern process-drawable-art-error symbol)
+(define-extern sprite-distorter-generate-tables (function none))