[REG] qdoc in 5.6: linking fails for certain functions

QDoc in 5.6 has improved capability to create a link to the correct function overload based on the number/types of function parameters. However, I noticed that some links are now failing, they used to work on 5.5:

/work/build/_qt5/qtdeclarative/examples/qml/doc/src/qml-extending.qdoc:65: warning: Can't link to 'qmlRegisterExtendedType()'
/work/build/_qt5/qtdeclarative/src/qml/doc/src/cppintegration/definetypes.qdoc:27: warning: Can't link to 'qmlRegisterExtendedType()'
/work/build/_qt5/qtbase/src/corelib/kernel/qmetatype.cpp:2080: warning: Can't link to 'qRegisterMetaTypeStreamOperators()'
/work/build/_qt5/qtbase/src/corelib/kernel/qmimedata.cpp:552: warning: Can't link to 'qRegisterMetaTypeStreamOperators()'

• Both of the above functions have an internal/undocumented variant (that takes no parameters) in the root namespace, and another, documented one (that takes parameters). Apparently QDoc finds the first one (as it matches the signature exactly) and gives up as it's internal. The expected result is a link to these functions:

http://doc-snapshots.qt.io/qt5-5.6/qqmlengine.html#qmlRegisterExtendedType

http://doc-snapshots.qt.io/qt5-5.6/qmetatype.html#qRegisterMetaTypeStreamOperators