[binutils-gdb] Move exception_none to common code, and use it

[sergiodj+buildbot@redhat.com]

*** TEST RESULTS FOR COMMIT ad6aff7dead678cc0fa4f786fa59c6040c6fa758 ***

Author: Pedro Alves <palves@redhat.com>
Branch: master
Commit: ad6aff7dead678cc0fa4f786fa59c6040c6fa758

Move exception_none to common code, and use it
gdb/ChangeLog:
2015-02-27  Pedro Alves  <palves@redhat.com>

	* common/common-exceptions.h (exception_none): Declare.
	* common/common-exceptions.c (exception_none): Moved from
	exceptions.c.
	(exceptions_state_mc_init): Use exception_none.
	* exceptions.c (exception_none): Move to
	common/common-exceptions.c.
	* exceptions.h (exception_none): Move to
	common/common-exceptions.h.