systemc: Add the nonstandard triggered function sc_event.

The Accellera implementation of sc_event has a non-standard triggered
function which returns whether or not that particular event has been
triggered in the current delta cycle. The tests call it, so we probably
need to have it.

Change-Id: I675099b65d00e09536618d4d2d707bf3c25e3bde
Reviewed-on: https://gem5-review.googlesource.com/11187
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>

src/systemc/core/sc_event.cc

@@ -277,6 +277,13 @@ sc_event::cancel()
     warn("%s not implemented.\n", __PRETTY_FUNCTION__);
 }
 
+bool
+sc_event::triggered() const
+{
+    warn("%s not implemented.\n", __PRETTY_FUNCTION__);
+    return false;
+}
+
 sc_event_and_expr
 sc_event::operator & (const sc_event &) const
 {

src/systemc/ext/core/sc_event.hh

@@ -132,6 +132,10 @@ class sc_event
     void notify(double, sc_time_unit);
     void cancel();
 
+    // Nonstandard
+    // Returns whether this event is currently triggered.
+    bool triggered() const;
+
     sc_event_and_expr operator & (const sc_event &) const;
     sc_event_and_expr operator & (const sc_event_and_list &) const;
     sc_event_or_expr operator | (const sc_event &) const;