Always check var shadowing, disable associated warning by default

src-json/warning.json

@@ -76,7 +76,8 @@
 	{
 		"name": "WVarShadow",
 		"doc": "A local variable hides another by using the same name",
-		"parent": "WTyper"
+		"parent": "WTyper",
+		"enabled": false
 	},
 	{
 		"name": "WExternWithExpr",

src/context/typecore.ml

@@ -416,7 +416,7 @@ let save_locals ctx =
 
 let add_local ctx k n t p =
 	let v = alloc_var k n t p in
-	if Define.defined ctx.com.defines Define.WarnVarShadowing && n <> "_" then begin
+	if n <> "_" then begin
 		match k with
 		| VUser _ ->
 			begin try