Modify lldbtest.Base.runHooks() to now take the following keyword arguments:

    child=None, child_prompt=None, use_cmd_api=False

By default, expect a pexpect spawned child and child prompt to be
supplied (use_cmd_api=False).  If use_cmd_api is true, ignore the child
and child prompt and use self.runCmd() to run the hooks one by one.

Modify existing client to reflect the change.

llvm-svn: 142532