unbreak infcalls

I managed to miss an interaction between the recent *running patch,
and target-async, which resulted in infcalls being completely broken
on GNU/Linux and remote targets (that is, the async-capable targets).

 Temporary breakpoint 1, main () at threads.c:35
 35          long i = 0;
 (gdb) p malloc (0)
 The program being debugged stopped while in a function called from GDB.
 Evaluation of the expression containing the function
 (malloc) will be abandoned.
 When the function is done executing, GDB will silently stop.
 (gdb) p malloc (0)

 Program received signal SIGSEGV, Segmentation fault.
 0x000000000058d7e8 in get_regcache_aspace (regcache=0x0) at ../../src/gdb/regcache.c:281
 281       return regcache->aspace;
 (top-gdb)

The issue is that when running an infcall, the thread is no longer
marked as running, so run_inferior_call is not calling
wait_for_inferior anymore.

Fix this by doing what the comment actually says we do:

  "Do here what `proceed' itself does in sync mode."

And proceed doesn't check whether the target is running.

I notice this is broken in case of the early return in proceed, but we
were broken before in that case anyway, because run_inferior_call will
think the call actually ran.  Seems like we should make proceed have a
boolean return, and go through all callers making use of it, if
necessary.

But for now, just fix the regression.

Tested on x86_64 Fedora 20.

gdb/
2014-05-29  Pedro Alves  <palves@redhat.com>

	* infcall.c (run_inferior_call): Don't check whether the current
	thread is running after the proceed call.
infrun.c: stop_stepping -> stop_waiting.

stop_stepping is called even when we weren't stepping.  It's job really is:

  static void
  stop_waiting (struct execution_control_state *ecs)
  {
  ...
    /* Let callers know we don't want to wait for the inferior anymore.  */
    ecs->wait_some_more = 0;
  }

So rename it for clarity.

gdb/
2014-05-29  Pedro Alves  <palves@redhat.com>

	* infrun.c (stop_stepping): Rename to ...
	(stop_waiting): ... this.
	(proceed): Update comment.
	(process_event_stop_test, handle_inferior_event)
	(handle_signal_stop, handle_step_into_function)
	(handle_step_into_function_backward): Update.
infrun.c: simplify "end stepping range" code a bit.

 - all end_stepping_range callers also set stop_step.

 - all places that set stop_step call end_stepping_range and
   stop_waiting too.

IOW, all places where we handle "end stepping range" do:

      ecs->event_thread->control.stop_step = 1;
      end_stepping_range ();
      stop_waiting (ecs);

Factor that out into end_stepping_range itself.

Tested on x86_64 Fedora 20.

gdb/
2014-05-29  Pedro Alves  <palves@redhat.com>

	* infrun.c (process_event_stop_test, handle_step_into_function)
	(handle_step_into_function_backward): Adjust.
	Don't set the even thread's stop_step and call stop_waiting before
	calling end_stepping_range.  Instead do that ...
	(end_stepping_range): ... here.  Take an ecs pointer parameter.