Infrastructure change: module descriptor now knows its platform kind & its sources kind

js/js.frontend/src/org/jetbrains/kotlin/js/resolve/JsPlatform.kt

@@ -18,6 +18,7 @@ package org.jetbrains.kotlin.js.resolve
 
 import org.jetbrains.kotlin.builtins.DefaultBuiltIns
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.descriptors.PlatformKind
 import org.jetbrains.kotlin.resolve.ImportPath
 import org.jetbrains.kotlin.resolve.PlatformConfigurator
 import org.jetbrains.kotlin.resolve.TargetPlatform
@@ -29,4 +30,8 @@ object JsPlatform : TargetPlatform("JS") {
 
     val builtIns: KotlinBuiltIns
         get() = DefaultBuiltIns.Instance
+
+    override val kind: PlatformKind
+        get() = PlatformKind.JS
+
 }