Allow JS Symbols

Author: mbovel

compiler/src/dotty/tools/dotc/core/Definitions.scala

@@ -500,6 +500,7 @@ class Definitions {
   @tu lazy val DummyImplicitClass: ClassSymbol = requiredClass("scala.DummyImplicit")
 
   @tu lazy val SymbolModule: Symbol = requiredModule("scala.Symbol")
+  @tu lazy val JSSymbolModule: Symbol = requiredModule("scala.scalajs.js.Symbol")
 
   @tu lazy val ScalaRuntimeModule: Symbol = requiredModule("scala.runtime.ScalaRunTime")
     def runtimeMethodRef(name: PreName): TermRef = ScalaRuntimeModule.requiredMethodRef(name)

compiler/src/dotty/tools/dotc/typer/Checking.scala

@@ -958,6 +958,7 @@ object Checking {
           qual.symbol == defn.ArrayModule
           || qual.symbol == defn.ClassTagModule // class tags are used as arguments to Array.apply
           || qual.symbol == defn.SymbolModule // used in Akka
+          || qual.symbol == defn.JSSymbolModule // used in Scala.js
           || isTupleModule(qual.symbol)
         case Select(New(clazz), nme.CONSTRUCTOR) => clazz.symbol.isAnnotation
         case Apply(fun, _) => isFunctionAllowed(fun)