Mark functions with 'operator' in JS stdlib

libraries/tools/kotlin-stdlib-gen/src/templates/SpecialJS.kt

@@ -91,6 +91,8 @@ fun specialJS(): List<GenericFunction> {
 
 
     templates add f("plus(element: T)") {
+        operator(true)
+
         only(ArraysOfObjects, ArraysOfPrimitives)
         returns("SELF")
         returns(ArraysOfObjects) { "Array<T>" }
@@ -105,6 +107,8 @@ fun specialJS(): List<GenericFunction> {
     }
 
     templates add f("plus(elements: Collection<T>)") {
+        operator(true)
+
         only(ArraysOfObjects, ArraysOfPrimitives)
         returns("SELF")
         returns(ArraysOfObjects) { "Array<T>" }
@@ -118,6 +122,8 @@ fun specialJS(): List<GenericFunction> {
 
     // This overload can cause nulls if array size is expanding, hence different return overload
     templates add f("plus(elements: SELF)") {
+        operator(true)
+
         only(ArraysOfObjects, ArraysOfPrimitives)
         doc { "Returns an array containing all elements of the original array and then all elements of the given [elements] array." }
         inline(true)