GDB uses the vRun packet if available to restart a running process in extended remote mode. Support this like the R packet and set the semihosting command-line to allow it to be specified from GDB. Change-Id: I9cb812b22170630f782113c9927e46e0cd5b1f0f Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com> Reviewed-on: http://openocd.zylin.com/5186 Tested-by: jenkins Reviewed-by: Tomas Vanek <vanekt@fbl.cz> Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>