Merge a number of assertion failure fixes to the 3.0 branch.

src/handles.cc

 // 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 790 matching lines @@
 bool EnsureCompiled(Handle<SharedFunctionInfo> shared,
                     ClearExceptionFlag flag) {
   return shared->is_compiled() || CompileLazyShared(shared, flag);
 }
 
 
 static bool CompileLazyHelper(CompilationInfo* info,
                               ClearExceptionFlag flag) {
   // Compile the source information to a code object.
   ASSERT(info->IsOptimizing() || !info->shared_info()->is_compiled());
+  ASSERT(!Top::has_pending_exception());
   bool result = Compiler::CompileLazy(info);
   ASSERT(result != Top::has_pending_exception());
   if (!result && flag == CLEAR_EXCEPTION) Top::clear_pending_exception();
   return result;
 }
 
 
 bool CompileLazyShared(Handle<SharedFunctionInfo> shared,
                        ClearExceptionFlag flag) {
   CompilationInfo info(shared);
@@ skipping 70 matching lines @@
 
 OptimizedObjectForAddingMultipleProperties::
 ~OptimizedObjectForAddingMultipleProperties() {
   // Reoptimize the object to allow fast property access.
   if (has_been_transformed_) {
     TransformToFastProperties(object_, unused_property_fields_);
   }
 }
 
 } }  // namespace v8::internal