Fix libs warnings

libs/extlib-leftovers/dune

@@ -2,7 +2,7 @@
 
 (env
 	(_
-		(flags (-w -27 -w -32))
+		(flags (-w -3 -w -27 -w -32))
 	)
 )
 

libs/ilib/dune

@@ -2,7 +2,7 @@
 
 (env
 	(_
-		(flags (-w -27))
+		(flags (-w -3 -w -27))
 	)
 )
 

libs/neko/ncompile.ml

@@ -673,8 +673,8 @@ and compile_builtin ctx tail b el p =
 			write ctx (Call 1);
 			(* // insert an infinite loop in order to
 			// comply with bytecode checker *)
-			let _ = jmp ctx in
-			()
+			let _jmp = jmp ctx in
+			ignore(_jmp)
 		) dtraps;
 	| ("goto" , _) ->
 		error "Invalid $goto statement" p

libs/swflib/dune

@@ -2,7 +2,7 @@
 
 (env
 	(_
-		(flags (-w -27))
+		(flags (-w -3 -w -27))
 	)
 )
 

libs/ttflib/dune

@@ -2,7 +2,7 @@
 
 (env
 	(_
-		(flags (-w -27 -w -35))
+		(flags (-w -3 -w -27 -w -35))
 	)
 )
 

libs/ziplib/dune

@@ -2,7 +2,7 @@
 
 (env
 	(_
-		(flags (-w -27 -w -35 -w -50))
+		(flags (-w -3 -w -27 -w -35 -w -50))
 	)
 )