Update the amalgamation builder to incorporate the RTREE extension. (CVS 5160)

FossilOrigin-Name: aa8eba3360c31182f5238e96b83a382374f40fab

ext/rtree/rtree.h

@@ -0,0 +1,26 @@
+/*
+** 2008 May 26
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This header file is used by programs that want to link against the
+** RTREE library.  All it does is declare the sqlite3RtreeInit() interface.
+*/
+#include "sqlite3.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif  /* __cplusplus */
+
+int sqlite3RtreeInit(sqlite3 *db);
+
+#ifdef __cplusplus
+}  /* extern "C" */
+#endif  /* __cplusplus */