messages.js: Get better function names in stack traces.

test/mjsunit/stack-traces.js

Index: test/mjsunit/stack-traces.js
diff --git a/test/mjsunit/stack-traces.js b/test/mjsunit/stack-traces.js
index 536e71bbb58a33a5ad6e2db9bae34fc9e6034a7f..438eec979d1766ed831a45c594bc29b8e9beab7a 100644
--- a/test/mjsunit/stack-traces.js
+++ b/test/mjsunit/stack-traces.js
@@ -111,6 +111,18 @@ function testStrippedCustomError() {
   throw new CustomError("hep-hey", CustomError);
 }
 
+MyObj = function() { FAIL; }
+
+MyObjCreator = function() {}
+
+MyObjCreator.prototype.Create = function() {
+  return new MyObj();
+}
+
+function testClassNames() {
+  (new MyObjCreator).Create();
+}
+
 // Utility function for testing that the expected strings occur
 // in the stack trace produced when running the given function.
 function testTrace(name, fun, expected, unexpected) {
@@ -254,6 +266,8 @@ testTrace("testDefaultCustomError", testDefaultCustomError,
     ["collectStackTrace"]);
 testTrace("testStrippedCustomError", testStrippedCustomError, ["hep-hey"],
     ["new CustomError", "collectStackTrace"]);
+testTrace("testClassNames", testClassNames,
+          ["new MyObj", "MyObjCreator.Create"], ["as Create"]);
 testCallerCensorship();
 testUnintendedCallerCensorship();
 testErrorsDuringFormatting();