Include qqmlglobal_p.h in tst_qmltyperegistrar.cpp to fix build

Fixes build error from testing for an unknown feature flag, i.e.

tst_qmltyperegistrar.cpp:1439:6: error: division by zero in preprocessor
expression

As it's a private feature, include a private header.

Pick-to: 6.10
Change-Id: I6112d73ebb738a555c05211d8f6c29a053de7b39
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

tests/auto/qml/qmltyperegistrar/tst_qmltyperegistrar.cpp

@@ -13,6 +13,7 @@
 #include <QtQml/qqmlengine.h>
 #include <QtQml/qqmlprivate.h>
 #include <QtQml/qtqmlglobal.h>
+#include <QtQml/private/qtqmlglobal_p.h>
 
 #include <QtCore/qcoreapplication.h>
 #include <QtCore/qfile.h>