Fix C++17 compile errors

indra/llcommon/llsd.h

indra/llcommon/llstl.h

indra/llinventory/llparcel.cpp

indra/llmessage/llcircuit.cpp

indra/llmessage/lldispatcher.cpp

indra/llmessage/llmessagethrottle.cpp

indra/llui/lldockablefloater.h

indra/newview/llappearancemgr.h

indra/newview/llfavoritesbar.cpp

indra/newview/llfloaterregioninfo.cpp

indra/newview/llgesturemgr.cpp

indra/newview/llmachineid.cpp

indra/newview/llpaneloutfitedit.h

indra/newview/llpaneloutfitsinventory.h

indra/newview/lltoast.h

indra/newview/llwatchdog.cpp

indra/test/lldoubledispatch_tut.cpp