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.