In order to generate metadata for a class `NS::Class`, moc will
"mangle" its name by turning the colons into underscores. This
however makes the generated name have a double underscore, and
all names with double underscores are reserved.
Instead, replace double colons with another string ("SCOPE").
We are then going to use this mangled name to create other identifiers.
To do so, underscores may get appended and prepended to the mangled name
(e.g. "qt_metadata_" + mangled_name + "_t"). This means that a leading
or trailing underscore in the mangled name would also be problematic;
avoid that as well.
Pick-to: 6.5
Fixes: QTBUG-109851
Change-Id: I01391a57920545fc75f78ef4bfefaf6d3dd7b447
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
e816f91541