Implement simple run for non-multithreaded TTS.

Since setting the maximum number of threads to use to 1 causes sporadically
files missing add a simple alternative implementation that doesn't use futures.
This is a stop-gap solution to fix voice files not creating (reported on
Windows with SAPI voices, see FS#11994). Encoding doesn't seem to be affected
by the problem and is unchanged.



git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29762 a1c6a512-1295-4272-9138-f99709370657

rbutil/rbutilqt/base/talkgenerator.h

@@ -94,6 +94,7 @@ private:
     EncBase* m_enc;
 
     bool m_ttsWarnings;
+    bool m_userAborted;
 };