Fix SharedFunctionInfo::name flattening nosnap failures

src/factory.cc

 // Copyright 2014 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.
 
 #include "src/factory.h"
 
 #include "src/allocation-site-scopes.h"
 #include "src/base/bits.h"
 #include "src/bootstrapper.h"
 #include "src/conversions.h"
@@ skipping 2101 matching lines @@
   message_obj->set_start_position(start_position);
   message_obj->set_end_position(end_position);
   message_obj->set_script(*script);
   message_obj->set_stack_frames(*stack_frames);
   return message_obj;
 }
 
 
 Handle<SharedFunctionInfo> Factory::NewSharedFunctionInfo(
     Handle<String> name, MaybeHandle<Code> maybe_code, bool is_constructor) {
+  // Function names are assumed to be flat elsewhere. Must flatten before
+  // allocating SharedFunctionInfo to avoid GC seeing the uninitialized SFI.
+  name = String::Flatten(name, TENURED);
+
   Handle<Map> map = shared_function_info_map();
   Handle<SharedFunctionInfo> share = New<SharedFunctionInfo>(map, OLD_SPACE);
 
   // Set pointer fields.
-  name = String::Flatten(name, TENURED);
   share->set_name(*name);
   Handle<Code> code;
   if (!maybe_code.ToHandle(&code)) {
     code = isolate()->builtins()->Illegal();
   }
   share->set_code(*code);
   share->set_optimized_code_map(*cleared_optimized_code_map());
   share->set_scope_info(ScopeInfo::Empty(isolate()));
   Handle<Code> construct_stub =
       is_constructor ? isolate()->builtins()->JSConstructStubGeneric()
@@ skipping 261 matching lines @@
 }
 
 
 Handle<Object> Factory::ToBoolean(bool value) {
   return value ? true_value() : false_value();
 }
 
 
 }  // namespace internal
 }  // namespace v8