Build fix if using '-no-stl' configure option

MSVC2010SP1:
error C3861: 'wmemcpy': identifier not found

Change-Id: Ib28edb5e38d691635c56dac846134e1c88c3f312
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>

src/plugins/platforms/windows/qwindowsfontdatabase.cpp

@@ -51,6 +51,8 @@
 #include <QtCore/qmath.h>
 #include <QtCore/QDebug>
 
+#include <wchar.h>
+
 #if !defined(QT_NO_DIRECTWRITE)
 #    include <dwrite.h>
 #    include <d2d1.h>

src/plugins/platforms/windows/qwindowsfontdatabase_ft.cpp

@@ -51,6 +51,8 @@
 #include <QtGui/QGuiApplication>
 #include <QtGui/QFontDatabase>
 
+#include <wchar.h>
+
 static inline QFontDatabase::WritingSystem writingSystemFromScript(const QString &scriptName)
 {
     if (scriptName == QStringLiteral("Western")