fix

Author: sjrd

compiler/src/dotty/tools/backend/sjs/JSCodeGen.scala

@@ -1677,7 +1677,7 @@ class JSCodeGen()(implicit ctx: Context) {
         } else if (isJSBracketAccess(sym)) {
           assert(noSpread && (argc == 1 || argc == 2),
               s"@JSBracketAccess methods should have 1 or 2 non-varargs arguments")
-          args match {
+          (args: @unchecked) match {
             case List(keyArg) =>
               genSelectGet(requireNotSpread(keyArg))
             case List(keyArg, valueArg) =>
@@ -2066,7 +2066,7 @@ class JSCodeGen()(implicit ctx: Context) {
     toTypeRef(tpe) match {
       case jstpe.ClassRef(cls) if ir.Definitions.PrimitiveClasses.contains(cls) =>
         assert(cls.length == 1)
-        (cls.charAt(0): @switch) match {
+        cls.charAt(0) match {
           case 'V' =>
             expr
           case primitiveCharCode =>