New additions/bug fixes required/found when porting perf.

New functions:
	tfind
	tsearch
	tdelete
	twalk
	tdestroy (GNU extension)

Bug fix: the current implementation for realpath would crash
	if the second argument (resolved_path) is NULL.

New headers:
	ar.h
	search.h

Change-Id: Ib6c1e42fc186a6d597a6e5a9692b16acaa155804
diff --git a/libc/bionic/tdestroy.c b/libc/bionic/tdestroy.c
new file mode 100644
index 0000000..70b71f4
--- /dev/null
+++ b/libc/bionic/tdestroy.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2012, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define _SEARCH_PRIVATE
+#include <search.h>
+#include <stdlib.h>
+
+/* destroy a tree and free all allocated resources */
+void
+tdestroy(void *root, void (*destroy_func)(void *))
+{
+    node_t *root_node = (node_t *) root;
+    if (root_node == NULL) return;
+    if (root_node->llink)
+        tdestroy(root_node->llink, destroy_func);
+    if (root_node->rlink)
+        tdestroy(root_node->rlink, destroy_func);
+    (*destroy_func)(root_node->key);
+    free(root);
+}