Fix has_constant_parameter_count() confusion in LReturn

test/mjsunit/regress/regress-crbug-431602.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --always-opt
+
+var heap_number_producer = {y:1.5};
+heap_number_producer.y = 0;
+var heap_number_zero = heap_number_producer.y;
+var non_constant_eight = {};
+non_constant_eight = 8;
+
+function BreakIt() {
+  return heap_number_zero | (1 | non_constant_eight);
+}
+
+function expose(a, b, c) {
+  return b;
+}
+
+assertEquals(9, expose(8, 9, 10));
+assertEquals(9, expose(8, BreakIt(), 10));
+assertEquals(9, BreakIt());