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

src/ast/scopes.cc

 // Copyright 2012 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/ast/scopes.h"
 
 #include <set>
 
 #include "src/accessors.h"
 #include "src/ast/ast.h"
@@ skipping 2040 matching lines @@
     if (is_function_scope()) {
       AsDeclarationScope()->AllocateParameterLocals();
     }
     AsDeclarationScope()->AllocateReceiver();
   }
   AllocateNonParameterLocalsAndDeclaredGlobals();
 
   // Force allocation of a context for this scope if necessary. For a 'with'
   // scope and for a function scope that makes an 'eval' call we need a context,
   // even if no local variables were statically allocated in the scope.
-  // Likewise for modules.
+  // Likewise for modules and function scopes representing asm.js modules.
   bool must_have_context =
-      is_with_scope() || is_module_scope() ||
+      is_with_scope() || is_module_scope() || IsAsmModule() ||
       (is_function_scope() && calls_sloppy_eval()) ||
       (is_block_scope() && is_declaration_scope() && calls_sloppy_eval());
 
   // If we didn't allocate any locals in the local context, then we only
   // need the minimal number of slots if we must have a context.
   if (num_heap_slots_ == Context::MIN_CONTEXT_SLOTS && !must_have_context) {
     num_heap_slots_ = 0;
   }
 
   // Allocation done.
@@ skipping 46 matching lines @@
   Variable* function =
       is_function_scope() ? AsDeclarationScope()->function_var() : nullptr;
   bool is_function_var_in_context =
       function != nullptr && function->IsContextSlot();
   return num_heap_slots() - Context::MIN_CONTEXT_SLOTS -
          (is_function_var_in_context ? 1 : 0);
 }
 
 }  // namespace internal
 }  // namespace v8