[modules] Improve error messages.

src/ast/scopeinfo.cc

 // Copyright 2011 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 <stdlib.h>
 
 #include "src/ast/context-slot-cache.h"
 #include "src/ast/scopes.h"
 #include "src/ast/variables.h"
 #include "src/bootstrapper.h"
@@ skipping 849 matching lines @@
   }
 
   PrintF("}\n");
 }
 #endif  // DEBUG
 
 Handle<ModuleInfoEntry> ModuleInfoEntry::New(Isolate* isolate,
                                              Handle<Object> export_name,
                                              Handle<Object> local_name,
                                              Handle<Object> import_name,
-                                             Handle<Object> module_request) {
+                                             Handle<Object> module_request,
+                                             int beg_pos, int end_pos) {
   Handle<ModuleInfoEntry> result = isolate->factory()->NewModuleInfoEntry();
   result->set(kExportNameIndex, *export_name);
   result->set(kLocalNameIndex, *local_name);
   result->set(kImportNameIndex, *import_name);
   result->set(kModuleRequestIndex, *module_request);
+  result->set(kBegPosIndex, Smi::FromInt(beg_pos));
+  result->set(kEndPosIndex, Smi::FromInt(end_pos));
   return result;
 }
 
 Handle<ModuleInfo> ModuleInfo::New(Isolate* isolate, Zone* zone,
                                    ModuleDescriptor* descr) {
   // Serialize module requests.
   Handle<FixedArray> module_requests = isolate->factory()->NewFixedArray(
       static_cast<int>(descr->module_requests().size()));
   for (const auto& elem : descr->module_requests()) {
     module_requests->set(elem.second, *elem.first->string());
@@ skipping 56 matching lines @@
     if (String::cast(entry->local_name())->Equals(*local_name)) {
       return entry;
     }
   }
   UNREACHABLE();
   return Handle<ModuleInfoEntry>();
 }
 
 }  // namespace internal
 }  // namespace v8