[parser] Ensure asm.js modules always allocate context.

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 427 matching lines @@
 int ScopeInfo::ContextLength() {
   if (length() > 0) {
     int context_locals = ContextLocalCount();
     bool function_name_context_slot =
         FunctionVariableField::decode(Flags()) == CONTEXT;
     bool has_context = context_locals > 0 || function_name_context_slot ||
                        scope_type() == WITH_SCOPE ||
                        (scope_type() == BLOCK_SCOPE && CallsSloppyEval() &&
                         is_declaration_scope()) ||
                        (scope_type() == FUNCTION_SCOPE && CallsSloppyEval()) ||
+                       (scope_type() == FUNCTION_SCOPE && IsAsmModule()) ||
                        scope_type() == MODULE_SCOPE;
 
     if (has_context) {
       return Context::MIN_CONTEXT_SLOTS + context_locals +
              (function_name_context_slot ? 1 : 0);
     }
   }
   return 0;
 }
 
@@ skipping 510 matching lines @@
     if (String::cast(entry->local_name())->Equals(*local_name)) {
       return entry;
     }
   }
   UNREACHABLE();
   return Handle<ModuleInfoEntry>();
 }
 
 }  // namespace internal
 }  // namespace v8