mark for-loop variables

They have special semantics which allows generators to optimize a bit.

src/context/meta.ml

@@ -52,6 +52,7 @@ type strict_meta =
 	| Fixed
 	| FlatEnum
 	| Font
+	| ForLoopVariable
 	| Forward
 	| ForwardStatics
 	| From
@@ -247,6 +248,7 @@ let get_info = function
 	| Fixed -> ":fixed",("Delcares an anonymous object to have fixed fields",[ (*UsedOn TObjectDecl(_)*)])
 	| FlatEnum -> ":flatEnum",("Internally used to mark an enum as being flat, i.e. having no function constructors",[UsedOn TEnum; UsedInternally])
 	| Font -> ":font",("Embeds the given TrueType font into the class (must extend flash.text.Font)",[HasParam "TTF path";HasParam "Range String";UsedOn TClass])
+	| ForLoopVariable -> ":forLoopVariable",("Internally used to mark for-loop variables",[UsedInternally])
 	| Forward -> ":forward",("Forwards field access to underlying type",[HasParam "List of field names";UsedOn TAbstract])
 	| ForwardStatics -> ":forwardStatics",("Forwards static field access to underlying type",[HasParam "List of field names";UsedOn TAbstract])
 	| From -> ":from",("Specifies that the field of the abstract is a cast operation from the type identified in the function",[UsedOn TAbstractField])

src/optimization/optimizer.ml

@@ -653,10 +653,10 @@ let rec type_inline ctx cf f ethis params tret config p ?(self_calling_closure=f
 
 (* Same as type_inline, but modifies the function body to add field inits *)
 and type_inline_ctor ctx c cf tf ethis el po =
-	let field_inits = 
+	let field_inits =
 		let cparams = List.map snd c.cl_params in
 		let ethis = mk (TConst TThis) (TInst (c,cparams)) c.cl_pos in
-		let el = List.fold_left (fun acc cf -> 
+		let el = List.fold_left (fun acc cf ->
 			match cf.cf_kind,cf.cf_expr with
 			| Var _,Some e ->
 				let lhs = mk (TField(ethis,FInstance (c,cparams,cf))) cf.cf_type e.epos in
@@ -688,6 +688,7 @@ let rec optimize_for_loop ctx (i,pi) e1 e2 p =
 	let gen_int_iter pt f_get f_length =
 		let i = add_local ctx i pt pi in
 		let index = gen_local ctx t_int pi in
+		index.v_meta <- (Meta.ForLoopVariable,[],null_pos) :: index.v_meta;
 		let arr, avars = (match e1.eexpr with
 			| TLocal _ -> e1, None
 			| _ ->
@@ -728,6 +729,7 @@ let rec optimize_for_loop ctx (i,pi) e1 e2 p =
 			| _ -> Some (gen_local ctx t_int e1.epos)
 		) in
 		let tmp = gen_local ctx t_int pi in
+		tmp.v_meta <- (Meta.ForLoopVariable,[],null_pos) :: tmp.v_meta;
 		let i = add_local ctx i t_int pi in
 		let rec check e =
 			match e.eexpr with