vpnor: Shuffle and rework includes for sanity

Include ordering and whether or not C linkage is forced by `extern "C"`
blocks can cause headaches at link time. Ensure that all C dependencies
are included in an `extern C` block before other includes occur. Also
include the C++ versions of string.h and assert.h

Change-Id: Ia96f6044d40c8eccb907b65924efcf62ac7a89c3
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/vpnor/test/create_read_window_partition_invalid.cpp b/vpnor/test/create_read_window_partition_invalid.cpp
index e6747c8..36431d3 100644
--- a/vpnor/test/create_read_window_partition_invalid.cpp
+++ b/vpnor/test/create_read_window_partition_invalid.cpp
@@ -3,11 +3,6 @@
 
 #include "config.h"
 
-#include <assert.h>
-#include <string.h>
-
-#include "vpnor/mboxd_pnor_partition_table.h"
-
 extern "C" {
 #include "test/mbox.h"
 #include "test/system.h"
@@ -15,6 +10,11 @@
 
 #include "vpnor/test/tmpd.hpp"
 
+#include <cassert>
+#include <cstring>
+
+#include "vpnor/mboxd_pnor_partition_table.h"
+
 const std::string toc[] = {
     "partition01=HBB,00002000,00003000,80,ECC,READONLY",
 };