Reorganize stdlib-js sources specific to the current JS backend

Move kotlin-stdlib-js project and the sources specific to the current backend to 'stdlib/js-v1' directory,
but leave sources that can be shared with the new IR backend in the common 'stdlib/js' location
with exception for 'stdlib/js/src/generated', which is used exclusively for current backend.
This simplifies sourceset configuration when building stdlib with the new backend.

libraries/stdlib/js-ir/runtime/noPackageHacks.kt

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2010-2018 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.
+ */
+
+/** Concat regular Array's and TypedArray's into an Array.
+ */
+@PublishedApi
+internal fun <T> arrayConcat(vararg args: T): T {
+    val len = args.size
+    val typed = js("Array(len)").unsafeCast<Array<T>>()
+    for (i in 0 .. (len - 1)) {
+        val arr = args[i]
+        if (arr !is Array<*>) {
+            typed[i] = js("[]").slice.call(arr)
+        } else {
+            typed[i] = arr
+        }
+    }
+    return js("[]").concat.apply(js("[]"), typed);
+}
+
+/** Concat primitive arrays. Main use: prepare vararg arguments.
+ */
+@PublishedApi
+internal fun <T> primitiveArrayConcat(vararg args: T): T {
+    var size_local = 0
+    for (i in 0 .. (args.size - 1)) {
+        size_local += args[i].unsafeCast<Array<Any?>>().size
+    }
+    val a = args[0]
+    val result = js("new a.constructor(size_local)").unsafeCast<Array<Any?>>()
+    if (a.asDynamic().`$type$` != null) {
+        withType(a.asDynamic().`$type$`, result)
+    }
+
+    size_local = 0
+    for (i in 0 .. (args.size - 1)) {
+        val arr = args[i].unsafeCast<Array<Any?>>()
+        for (j in 0 .. (arr.size - 1)) {
+            result[size_local++] = arr[j]
+        }
+    }
+    return result.unsafeCast<T>()
+}
+
+@PublishedApi
+internal inline fun withType(type: String, array: dynamic): dynamic {
+    array.`$type$` = type
+    return array
+}