Eagerly format traces in captureStackTrace

test/mjsunit/stack-traces.js

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 362 matching lines @@
 error.__defineGetter__("name", function() { error.stack = "abc"; });
 assertEquals("abc", error.stack);
 
 error = new Error();
 error.__defineGetter__("name", function() { delete error.stack; });
 assertEquals(undefined, error.stack);
 
 // Check that repeated trace collection does not crash.
 error = new Error();
 Error.captureStackTrace(error);
+
+// Check that exceptions thrown within prepareStackTrace throws an exception.
+Error.prepareStackTrace = function(e, frames) { throw 42; }
+
+var x = {}
+assertThrows(() => Error.captureStackTrace(x));