Revert "SL-16220: Merge branch 'origin/DRTVWR-546' into glthread"

indra/llcommon/CMakeLists.txt

indra/llcommon/llsingleton.h

indra/llcommon/llthreadsafequeue.h

indra/llcommon/tests/threadsafeschedule_test.cpp

indra/llcommon/tests/workqueue_test.cpp

indra/llcommon/threadpool.cpp

indra/llcommon/threadpool.h

indra/llcommon/timing.cpp

indra/llcommon/workqueue.cpp

indra/llcommon/workqueue.h

indra/llrender/llimagegl.cpp

indra/llrender/llimagegl.h

indra/llui/CMakeLists.txt

indra/llui/llviewereventrecorder.cpp

indra/llwindow/llwindowwin32.cpp

indra/llwindow/llwindowwin32.h

indra/newview/CMakeLists.txt

indra/newview/app_settings/settings.xml

indra/newview/llappviewer.cpp

indra/newview/llenvironment.cpp