QComposePlatformInputContextPlugin: includemocs

Including moc files directly into their classes' TU tends to improve
codegen and enables extended compiler warnings, e.g. about unused
private functions or fields.

Pick-to: 6.3 6.2 5.15
Task-number: QTBUG-102886
Change-Id: Ie56a3b402ee8e1ed258a3b7e12dae3eb663bc03d
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/plugins/platforminputcontexts/compose/qcomposeplatforminputcontext.cpp

@@ -171,3 +171,5 @@ void QComposeInputContext::update(Qt::InputMethodQueries q)
 }
 
 QT_END_NAMESPACE
+
+#include "moc_qcomposeplatforminputcontext.cpp"