Change the default implementation of to_traceframe_info to tcomplain

This patch is to change the default implementation of to_traceframe_info
from 'return NULL' to tcomplain, which is intended.  If new target
supports tracepoint, this method should be implemented, otherwise,
an error is thrown.

gdb:

2014-03-06  Yao Qi  <yao@codesourcery.com>

	* target.h (struct target_ops) <to_traceframe_info>: Use
	TARGET_DEFAULT_NORETURN (tcomplain ()).
	* target-delegates.c: Regenerated.