Instead of deep inside the processing of the message pattern tokens.
This reduces the number of uninlineable functions in release builds to
2. Experimentation shows that even in debug mode our overhead to
backtrace() is just 2, despite the debugger's backtrace showing 3 frames
-- the debugger is using QtCore's debug symbols and does know about the
inlined function.
As a nice side-effect, we capture the backtrace only once per message,
not once per %{backtrace} token in the QT_MESSAGE_PATTERN.
Change-Id: I01ec3c774d9943adb903fffd17b7d6de09167620
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
710276ed85