repositioned #include for libxml.h to avoid compilation error on some

* testAutomata.c, testRegexp.c, testThreads.c, testThreadsWin32.c,
  xmlwriter.c: repositioned #include for libxml.h to avoid
  compilation error on some architectures (bug #398277)

svn path=/trunk/; revision=3578
diff --git a/testThreads.c b/testThreads.c
index 6405a77..b43cbd0 100644
--- a/testThreads.c
+++ b/testThreads.c
@@ -1,6 +1,7 @@
+#include "libxml.h"
+
 #include <stdlib.h>
 #include <stdio.h>
-#include "libxml.h"
 
 #if defined(LIBXML_THREAD_ENABLED) && defined(LIBXML_CATALOG_ENABLED) && defined(LIBXML_SAX1_ENABLED)
 #include <libxml/globals.h>