Make Array.size() a function instead of a property

Also add a deprecated extension property to help migration. This is done to
unify getting size of arrays and collections

compiler/testData/codegen/box/classes/kt1018.kt

@@ -1,7 +1,7 @@
 public class StockMarketTableModel() {
 
     public fun getColumnCount() : Int {
-        return COLUMN_TITLES?.size!!
+        return COLUMN_TITLES?.size()!!
     }
 
     class object {