Propagate switch statement value for 'eval'

test/mjsunit/regress/regress-4399.js

+// Copyright 2015 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.
+
+// Test that switch has the appropriate 'eval' value
+
+assertEquals("foo", eval('switch(1) { case 1: "foo" }'));
+assertEquals("foo", eval('{ switch(1) { case 1: "foo" } }'));
+assertEquals("foo", eval('switch(1) { case 1: { "foo" } }'));
+assertEquals("foo", eval('switch(1) { case 1: "foo"; break; case 2: "bar"; break }'));
+assertEquals("bar", eval('switch(2) { case 1: "foo"; break; case 2: "bar"; break }'));
+assertEquals("bar", eval('switch(1) { case 1: "foo"; case 2: "bar"; break }'));
+
+// The tag is not the value, if there's no value
+
+assertEquals(undefined, eval('switch (1) {}'));
+assertEquals(undefined, eval('switch (1) { case 1: {} }'));