Provide string-to-number conversions in JS and common stdlib.

Relates to #KT-8286
#KT-4497 Fixed

js/js.libraries/test/core/testUtils.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kotlin.test
+
+public fun assertTypeEquals(expected: Any?, actual: Any?) {
+    //TODO: find analogue
+    //assertEquals(expected?.javaClass, actual?.javaClass)
+}
+
+internal inline fun String.removeLeadingPlusOnJava6(): String = this
+internal fun doubleTotalOrderEquals(a: Double?, b: Double?) = a == b || (a != a && b != b)