bring back "Generated by Haxe ..." headers

src/context/common.ml

@@ -644,7 +644,7 @@ let create version s_version args =
 	let m = Type.mk_mono() in
 	let defines =
 		PMap.add "true" "1" (
-			PMap.add "source-header" ("Generated by Haxe " ^ s_version) PMap.empty
+			PMap.add "source_header" ("Generated by Haxe " ^ s_version) PMap.empty
 		)
 	in
 	{