[error] Clear external_caught_exception in Error formatting

test/mjsunit/regress/regress-719380.js

Index: test/mjsunit/regress/regress-719380.js
diff --git a/test/mjsunit/regress/regress-719380.js b/test/mjsunit/regress/regress-719380.js
new file mode 100644
index 0000000000000000000000000000000000000000..18d541a5fe675855861362ebae69ec876827868f
--- /dev/null
+++ b/test/mjsunit/regress/regress-719380.js
@@ -0,0 +1,7 @@
+// Copyright 2017 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.
+
+TypeError.prototype.__defineGetter__("name", () => { throw 42; });
+console.log({ toString: () => { throw new TypeError() }});
+try { new WebAssembly.Table({}); } catch (e) {}