--- old/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/ConsString.java	2020-04-15 18:49:43.000000000 +0530
+++ /dev/null	2020-04-15 18:49:43.000000000 +0530
@@ -1,139 +0,0 @@
-/*
- * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package jdk.nashorn.internal.runtime;
-
-import static jdk.nashorn.internal.runtime.JSType.isString;
-
-import java.util.ArrayDeque;
-import java.util.Deque;
-
-/**
- * This class represents a string composed of two parts which may themselves be
- * instances of <code>ConsString</code> or {@link String}. Copying of characters to
- * a proper string is delayed until it becomes necessary.
- */
-public final class ConsString implements CharSequence {
-
-    private CharSequence left, right;
-    private final int length;
-    private volatile int state = STATE_NEW;
-
-    private final static int STATE_NEW       =  0;
-    private final static int STATE_THRESHOLD =  2;
-    private final static int STATE_FLATTENED = -1;
-
-    /**
-     * Constructor
-     *
-     * Takes two {@link CharSequence} instances that, concatenated, forms this {@code ConsString}
-     *
-     * @param left  left char sequence
-     * @param right right char sequence
-     */
-    public ConsString(final CharSequence left, final CharSequence right) {
-        assert isString(left);
-        assert isString(right);
-        this.left = left;
-        this.right = right;
-        length = left.length() + right.length();
-        if (length < 0) {
-            throw new IllegalArgumentException("too big concatenated String");
-        }
-    }
-
-    @Override
-    public String toString() {
-        return (String) flattened(true);
-    }
-
-    @Override
-    public int length() {
-        return length;
-    }
-
-    @Override
-    public char charAt(final int index) {
-        return flattened(true).charAt(index);
-    }
-
-    @Override
-    public CharSequence subSequence(final int start, final int end) {
-        return flattened(true).subSequence(start, end);
-    }
-
-    /**
-     * Returns the components of this ConsString as a {@code CharSequence} array with two elements.
-     * The elements will be either {@code Strings} or other {@code ConsStrings}.
-     * @return CharSequence array of length 2
-     */
-    public synchronized CharSequence[] getComponents() {
-        return new CharSequence[] { left, right };
-    }
-
-    private CharSequence flattened(final boolean flattenNested) {
-        if (state != STATE_FLATTENED) {
-            flatten(flattenNested);
-        }
-        return left;
-    }
-
-    private synchronized void flatten(final boolean flattenNested) {
-        // We use iterative traversal as recursion may exceed the stack size limit.
-        final char[] chars = new char[length];
-        int pos = length;
-        // Strings are most often composed by appending to the end, which causes ConsStrings
-        // to be very unbalanced, with mostly single string elements on the right and a long
-        // linear list on the left. Traversing from right to left helps to keep the stack small
-        // in this scenario.
-        final Deque<CharSequence> stack = new ArrayDeque<>();
-        stack.addFirst(left);
-        CharSequence cs = right;
-
-        do {
-            if (cs instanceof ConsString) {
-                final ConsString cons = (ConsString) cs;
-                // Count the times a cons-string is traversed as part of other cons-strings being flattened.
-                // If it crosses a threshold we flatten the nested cons-string internally.
-                if (cons.state == STATE_FLATTENED || (flattenNested && ++cons.state >= STATE_THRESHOLD)) {
-                    cs = cons.flattened(false);
-                } else {
-                    stack.addFirst(cons.left);
-                    cs = cons.right;
-                }
-            } else {
-                final String str = (String) cs;
-                pos -= str.length();
-                str.getChars(0, str.length(), chars, pos);
-                cs = stack.isEmpty() ? null : stack.pollFirst();
-            }
-        } while (cs != null);
-
-        left = new String(chars);
-        right = "";
-        state = STATE_FLATTENED;
-    }
-
-}