Hi,
Recently, we find some failures in gdb testsute on ARM,

FAIL: gdb.base/watch-vfork.exp: Watchpoint triggers after vfork (hw)
(the program exited)
FAIL: gdb.base/watch-vfork.exp: Watchpoint triggers after vfork (sw)
(the program exited)

Program exits when we stepping over svc instruction in vfork(), which is
caused by child process hits software single step breakpoint inserted
for parent process.

This patch is to fix this problem by 'when inferior's
wait_for_vfork_done is true, clear step to zero and don't use displaced
stepping'.

Tested on GDB CVS on ARM and X86-64.  Fix these two failures above on
ARM, and no regressions.  OK to apply?

-- 
Yao Qi
CodeSourcery
yao@codesourcery.com
(650) 331-3385 x739