[modules] Introduce new VariableLocation for module imports/exports.

src/ast/prettyprinter.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/prettyprinter.h"
 
 #include <stdarg.h>
 
 #include "src/ast/ast-value-factory.h"
 #include "src/ast/scopes.h"
@@ skipping 1043 matching lines @@
         break;
       case VariableLocation::CONTEXT:
         SNPrintF(buf + pos, " context[%d]", var->index());
         break;
       case VariableLocation::GLOBAL:
         SNPrintF(buf + pos, " global[%d]", var->index());
         break;
       case VariableLocation::LOOKUP:
         SNPrintF(buf + pos, " lookup");
         break;
+      case VariableLocation::MODULE:
+        SNPrintF(buf + pos, " module");
+        break;
     }
     PrintLiteralWithModeIndented(buf.start(), var, node->name());
   }
 }
 
 
 void AstPrinter::VisitAssignment(Assignment* node) {
   IndentedScope indent(this, Token::Name(node->op()), node->position());
   Visit(node->target());
   Visit(node->value());
@@ skipping 113 matching lines @@
 
 void AstPrinter::VisitRewritableExpression(RewritableExpression* node) {
   Visit(node->expression());
 }
 
 
 #endif  // DEBUG
 
 }  // namespace internal
 }  // namespace v8