Revert "Revert "QVector: add a construction from QArrayDataPointerRef""

Removing the constructor caused a binary compatibility break. The symbol
is being used even though it might be considered private API.

This reverts commit bf82689.

Fixes: QTBUG-86392
Pick-to: 5.15
Change-Id: I04fc3058e68a6a0cf293bcc8a5a83031dc1e96fb
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
Reviewed-by: Ville Voutilainen <ville.voutilainen@qt.io>

Author: owolff

src/corelib/tools/qvector.h

@@ -80,6 +80,7 @@ class QVector
     QVector<T> &operator=(std::initializer_list<T> args);
     template <typename InputIterator, QtPrivate::IfIsInputIterator<InputIterator> = true>
     inline QVector(InputIterator first, InputIterator last);
+    explicit QVector(QArrayDataPointerRef<T> ref) noexcept : d(ref.ptr) {}
 
     bool operator==(const QVector<T> &v) const;
     inline bool operator!=(const QVector<T> &v) const { return !(*this == v); }

src/corelib/tools/qvector.qdoc

@@ -269,6 +269,11 @@
     The value type of \c InputIterator must be convertible to \c T.
 */
 
+/*!
+    \fn template <typename T> QVector<T>::QVector(QArrayDataPointerRef<T> ref)
+    \internal
+*/
+
 /*! \fn template <typename T> QVector<T>::~QVector()
 
     Destroys the vector.