Mantis#1314. Thank you kindly, Kinoc for YieldProlog.

I have added everything *except* the patch to 
.../LSL/Compiler.cs. The Compiler.cs patch has a 
namespace issue. Lets make a second patch to close
the gap.

OpenSim/Region/ScriptEngine/DotNetEngine/Compiler/YieldProlog/FindallAnswers.cs

@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2007-2008, Jeff Thompson
+ * 
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without 
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ *     * Redistributions of source code must retain the above copyright 
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright 
+ *       notice, this list of conditions and the following disclaimer in the 
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the copyright holder nor the names of its contributors 
+ *       may be used to endorse or promote products derived from this software 
+ *       without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace OpenSim.Region.ScriptEngine.DotNetEngine.Compiler.YieldProlog
+{
+    /// <summary>
+    /// A FindallAnswers holds answers for findall.
+    /// </summary>
+    public class FindallAnswers
+    {
+        private object _template;
+        private List<object> _bagArray;
+
+        public FindallAnswers(object Template)
+        {
+            _template = Template;
+            _bagArray = new List<object>();
+        }
+
+        public void add()
+        {
+            _bagArray.Add(YP.makeCopy(_template, new Variable.CopyStore()));
+        }
+
+        public List<object> resultArray()
+        {
+            return _bagArray;
+        }
+
+        /// <summary>
+        /// Unify Bag with the result. This frees the internal answers, so you can only call this once.
+        /// </summary>
+        /// <param name="Bag"></param>
+        /// <returns></returns>
+        public IEnumerable<bool> result(object Bag)
+        {
+            object result = ListPair.make(_bagArray);
+            // Try to free the memory.
+            _bagArray = null;
+            return YP.unify(Bag, result);
+        }
+
+        /// <summary>
+        /// This is a simplified findall when the goal is a single call.
+        /// </summary>
+        /// <param name="Template"></param>
+        /// <param name="goal"></param>
+        /// <param name="Bag"></param>
+        /// <returns></returns>
+        public static IEnumerable<bool> findall(object Template, IEnumerable<bool> goal, object Bag)
+        {
+            FindallAnswers findallAnswers = new FindallAnswers(Template);
+            foreach (bool l1 in goal)
+                findallAnswers.add();
+            return findallAnswers.result(Bag);
+        }
+
+        /// <summary>
+        /// Like findall, except return an array of the results.
+        /// </summary>
+        /// <param name="template"></param>
+        /// <param name="goal"></param>
+        /// <returns></returns>
+        public static List<object> findallArray(object Template, IEnumerable<bool> goal)
+        {
+            FindallAnswers findallAnswers = new FindallAnswers(Template);
+            foreach (bool l1 in goal)
+                findallAnswers.add();
+            return findallAnswers.resultArray();
+        }
+    }
+}