[Qt] Build fix on MSVC. Reverts r55633 for stdint.h

Reviewed by nobody, build fix.

This file gets included in generated moc files which don't
include the prefix header.

* os-win32/stdint.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@56528 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/JavaScriptCore/os-win32/stdint.h b/JavaScriptCore/os-win32/stdint.h
index 4bdec62..1d8787e 100644
--- a/JavaScriptCore/os-win32/stdint.h
+++ b/JavaScriptCore/os-win32/stdint.h
@@ -21,6 +21,7 @@
 #ifndef STDINT_WIN32_H
 #define STDINT_WIN32_H
 
+#include <wtf/Platform.h>
 
 /* This file emulates enough of stdint.h on Windows to make JavaScriptCore and WebCore
    compile using MSVC which does not ship with the stdint.h header. */