Support GrowsBackwards in QByteArray

Updated main QByteArray operations to support prepend-optimization path

There are still many things to consider especially algorithms that use
QByteArray::data() or do raw memory operations (e.g. memcpy) regardless
of the underlying memory layout, which was somewhat valid before but
will likely break now given free space > 0 at the beginning of the byte
array memory. Looked at existing cases in the scope of QByteArray, they
seem to be OK. Hopefully, CI would find missed violations if any

Task-number: QTBUG-84320
Change-Id: I7990cda165b8e77a397e41df4e145468e7a86be0
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

0 files changed, 0 insertions, 0 deletions