As a macro, we can't directly deprecate it, but need to make it call
something deprecated. That is a new ctor with a new enum type
added. The type might be useful for other such ventures, so put it
into qglobal.h
Remove the QT_NO_UNICODE_LITERAL protection, as it's always false
these days, and QT_UNICODE_LITERAL is unconditionally #defined a 20
lines above.
[ChangeLog][QtCore][QStringView] Deprecated the (undocumented)
QStringViewLiteral macro. Just use u"" or QStringView(u"") instead.
Change-Id: I9141320225037e1bc6b7f920bf01a9d0144fdac2
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>