Remove specialization of toTypedArray for LongArray and BooleanArray in JS

The default implementation for primitive arrays returns an array of correct type.

#KT-29187 Fixed

libraries/stdlib/js/irRuntime/generated/_ArraysJs.kt

@@ -1272,7 +1272,7 @@ public actual fun IntArray.toTypedArray(): Array<Int> {
  * Returns a *typed* object array containing all of the elements of this primitive array.
  */
 public actual fun LongArray.toTypedArray(): Array<Long> {
-    return copyOf().unsafeCast<Array<Long>>()
+    return js("[]").slice.call(this)
 }
 
 /**
@@ -1293,7 +1293,7 @@ public actual fun DoubleArray.toTypedArray(): Array<Double> {
  * Returns a *typed* object array containing all of the elements of this primitive array.
  */
 public actual fun BooleanArray.toTypedArray(): Array<Boolean> {
-    return copyOf().unsafeCast<Array<Boolean>>()
+    return js("[]").slice.call(this)
 }
 
 /**

libraries/stdlib/js/src/generated/_ArraysJs.kt

@@ -1308,7 +1308,7 @@ public actual fun IntArray.toTypedArray(): Array<Int> {
  * Returns a *typed* object array containing all of the elements of this primitive array.
  */
 public actual fun LongArray.toTypedArray(): Array<Long> {
-    return copyOf().unsafeCast<Array<Long>>()
+    return js("[]").slice.call(this)
 }
 
 /**
@@ -1329,7 +1329,7 @@ public actual fun DoubleArray.toTypedArray(): Array<Double> {
  * Returns a *typed* object array containing all of the elements of this primitive array.
  */
 public actual fun BooleanArray.toTypedArray(): Array<Boolean> {
-    return copyOf().unsafeCast<Array<Boolean>>()
+    return js("[]").slice.call(this)
 }
 
 /**

libraries/stdlib/js/test/collections/ArraysJsTest.kt

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package test.js.collections
+
+import kotlin.test.*
+
+class ArraysJsTest {
+    @Test
+    fun toTypedArrayIsObjectArray() {
+        fun checkIsObjectArray(array: Any, arrayType: String) = assertTrue(array is Array<*>, "$arrayType.toTypedArray() is not Array<*>")
+        checkIsObjectArray(intArrayOf(1).toTypedArray(), "IntArray")
+        checkIsObjectArray(longArrayOf(1).toTypedArray(), "LongArray")
+        checkIsObjectArray(charArrayOf('a').toTypedArray(), "CharArray")
+        checkIsObjectArray(booleanArrayOf(false).toTypedArray(), "BooleanArray")
+    }
+}

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

@@ -1070,8 +1070,6 @@ object ArrayOps : TemplateGroupBase() {
             on(Platform.JS) {
                 when (primitive) {
                     PrimitiveType.Char -> {}
-                    PrimitiveType.Boolean, PrimitiveType.Long ->
-                        body { "return copyOf().unsafeCast<Array<T>>()" }
                     else ->
                         body { "return js(\"[]\").slice.call(this)" }
                 }