Turn of concat output scheduling.

We really want lazy processing of concatenation because it has multiple
inputs and lazy processing should (in theory) prevent redundant and
useless propagations through the net.

But enabling it seems to cause many tests in the regression test suite
to fail to compare their results. There are races in many tests that
are interacting badly with this feature. So for now, ifdef it out.

vvp/concat.cc

@@ -28,6 +28,8 @@
 #endif
 # include  <assert.h>
 
+# define SCHEDULE_OUTPUT 0
+
 /* vvp_fun_concat
  * This node function creates vectors (vvp_vector4_t) from the
  * concatenation of the inputs. The inputs (4) may be vector or
@@ -84,9 +86,13 @@ void vvp_fun_concat::recv_vec4(vvp_net_ptr_t port, const vvp_vector4_t&bit)
 	    return;
 
       input_[pdx] = bit;
+
       if (net_ == 0) {
 	    net_ = port.ptr();
+	    if (SCHEDULE_OUTPUT)
 		  schedule_generic(this, 0, false);
+	    else
+		  run_run();
       }
 }