[debugger] ScopeIterator should unwrap debug-evaluate contexts.

test/mjsunit/debug-evaluate-nested.js

+// Copyright 2016 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: --expose-debug-as debug
+
+Debug = debug.Debug;
+ScopeType = debug.ScopeType;
+var exception = null;
+var nested = false;
+
+function bar() {
+  let a = 1;
+  (function foo() {
+    let b = a;
+    with (new Proxy({}, {})) {
+      debugger;
+    }
+  })();
+}
+
+function checkScopes(scopes, expectation) {
+  assertEquals(scopes.map(s => s.scopeType()), expectation);
+}
+
+function listener(event, exec_state, event_data, data) {
+  if (event != Debug.DebugEvent.Break) return;
+  try {
+    if (!nested) {
+      nested = true;
+      checkScopes(exec_state.frame(0).allScopes(),
+                  [ ScopeType.With, ScopeType.Local, ScopeType.Closure,
+                    ScopeType.Script, ScopeType.Global ]);
+      exec_state.frame(0).evaluate("debugger;");
+    } else {
+      checkScopes(exec_state.frame(0).allScopes(),
+                  [ ScopeType.With, ScopeType.Closure,
+                    ScopeType.Script, ScopeType.Global ]);
+    }
+  } catch (e) {
+    exception = e;
+    print(e + e.stack);
+  }
+}
+
+Debug.setListener(listener);
+bar();
+Debug.setListener(null);
+assertNull(exception);