feat(polyfills): use stdlib for js polyfills.

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

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package kotlin.js
+
+@JsNativeImplementation("""
+(function() {
+    if (typeof globalThis === 'object') return; 
+    Object.defineProperty(Object.prototype, '__magic__', {
+        get: function() {
+            return this;
+        },
+        configurable: true
+    });
+    __magic__.globalThis = __magic__;
+    delete Object.prototype.__magic__;
+}());
+""")
+internal external val globalThis: dynamic

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

@@ -0,0 +1,15 @@
+/*
+ * 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.
+ */
+@file:JsQualifier("Math")
+package kotlin.js
+
+@JsNativeImplementation("""
+if (typeof Math == "object" && Math !== null & typeof Math.imul === "undefined") {
+  Math.imul = function imul(a, b) {
+    return ((a & 0xffff0000) * (b & 0xffff) + (a & 0xffff) * (b | 0)) | 0; 
+  }
+}
+""")
+internal external fun imul(a_local: Int, b_local: Int): Int

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

@@ -1,13 +0,0 @@
-/*
- * 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.
- */
-
-package kotlin.js
-
-// TODO: Polyfill
-internal fun imul(a_local: Int, b_local: Int): Int {
-    val lhs = jsBitwiseAnd(a_local, js("0xffff0000")).toDouble() * jsBitwiseAnd(b_local, 0xffff).toDouble()
-    val rhs = jsBitwiseAnd(a_local, 0xffff).toDouble() * b_local.toDouble()
-    return jsBitwiseOr(lhs + rhs, 0)
-}

libraries/stdlib/js/src/kotlin/internalAnnotations.kt

@@ -0,0 +1,10 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package kotlin.js
+
+@Retention(AnnotationRetention.BINARY)
+@Target(AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY)
+internal annotation class JsNativeImplementation(val implementation: String)