When we run into a plugin that does not have a type and is not a
qml plugin, we try to see if we can find the target installation path
and provide INSTALL_DIRECTORY AND ARCHIVE_INSTALL_DIRECTORY to the
add_qt_plugin call.
We run into this frequently with the unit tests.
This patch also changes add_qt_plugin() to use the value provided in
INSTALL_DIRECTORY for ARCHIVE_INSTALL_DIRECTORY if no value is provided
for the latter.
Change-Id: I61278904a4d2d72308079cd362bd085b4e2f540c
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
b42feb02ce