Add JDK roots to the beginning of the roots list

This behavior was used until 6a1b6d10d8, where the JDK has
unintentionally started to be added to the end of the list, breaking
code which depended on libraries which bundle something from the JDK

 #KT-21299 Fixed

compiler/testData/compileKotlinAgainstCustomBinaries/classFromJdkInLibrary/library/java/util/Date.java

@@ -0,0 +1,5 @@
+package java.util;
+
+public class Date {
+    public static void methodWhichDoesNotExistInJdk() {}
+}