Fix Error.prototype.toString to throw TypeError.

test/mjsunit/function-call.js

Index: test/mjsunit/function-call.js
diff --git a/test/mjsunit/function-call.js b/test/mjsunit/function-call.js
index 06479ad4e826a3e94f40770f2d965d367197c81d..26890ed113c8bdeaa4376dc3ad39f4b752a11b75 100644
--- a/test/mjsunit/function-call.js
+++ b/test/mjsunit/function-call.js
@@ -68,8 +68,7 @@ var should_throw_on_null_and_undefined =
      String.prototype.toUpperCase,
      String.prototype.toLocaleUpperCase,
      String.prototype.trim,
-     Number.prototype.toLocaleString,
-     Error.prototype.toString];
+     Number.prototype.toLocaleString];
 
 // Non generic natives do not work on any input other than the specific
 // type, but since this change will allow call to be invoked with undefined
@@ -134,7 +133,8 @@ var non_generic =
      Date.prototype.toJSON,
      RegExp.prototype.exec,
      RegExp.prototype.test,
-     RegExp.prototype.toString];
+     RegExp.prototype.toString,
+     Error.prototype.toString];
 
 
 // Mapping functions.