Added copyToArray intrinsic method.

#KT-3352 fixed

compiler/testData/codegen/boxWithStdlib/toArray/kt3177-copyToArray.kt

@@ -0,0 +1,15 @@
+import java.util.ArrayList
+import java.util.Arrays
+
+fun box(): String {
+    val list = ArrayList<Pair<String,String>>()
+    list.add(Pair("Sample", "http://cyber.law.harvard.edu/rss/examples/rss2sample.xml"))
+    list.add(Pair("Scripting", "http://static.scripting.com/rss.xml"))
+
+    val keys = list.map { it.first }.copyToArray<String>()
+
+    val keysToString = Arrays.toString(keys)
+    if (keysToString != "[Sample, Scripting]") return keysToString
+
+    return "OK"
+}