using the gb_DBGARGS variable.

This value is appended to the gdb "set args" command.

Change-Id: Ic15754d7edcc448f283522338900684a29a03cf3
Reviewed-on: https://gerrit.libreoffice.org/21364Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>
Tested-by: Jan-Marek Glogowski <glogow@fbihome.de>