QFlatMap: don't sort already ordered data

Pick-to: 6.3 6.2
Change-Id: Id7ab2fe09c01500ca5bd23751ba29ed1394bb9b6
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

src/corelib/tools/qflatmap_p.h

@@ -493,7 +493,7 @@ public:
     }
 
     explicit QFlatMap(Qt::OrderedUniqueRange_t, std::initializer_list<value_type> lst)
-        : QFlatMap(lst.begin(), lst.end())
+        : QFlatMap(Qt::OrderedUniqueRange, lst.begin(), lst.end())
     {
     }