Rip out most of our outdated modules implementation.

src/ast/ast.h

Index: src/ast/ast.h
diff --git a/src/ast/ast.h b/src/ast/ast.h
index 71a2459d1824b8efe5aa145c51d9f6c75dd917c2..129147b13ce3fcecf4cf5b948eb92b0ea8a568b5 100644
--- a/src/ast/ast.h
+++ b/src/ast/ast.h
@@ -40,8 +40,7 @@ namespace internal {
 #define DECLARATION_NODE_LIST(V) \
   V(VariableDeclaration)         \
   V(FunctionDeclaration)         \
-  V(ImportDeclaration)           \
-  V(ExportDeclaration)
+  V(ImportDeclaration)
 
 #define STATEMENT_NODE_LIST(V)    \
   V(Block)                        \
@@ -603,20 +602,6 @@ class ImportDeclaration final : public Declaration {
 };
 
 
-class ExportDeclaration final : public Declaration {
- public:
-  DECLARE_NODE_TYPE(ExportDeclaration)
-
-  InitializationFlag initialization() const override {
-    return kCreatedInitialized;
-  }
-
- protected:
-  ExportDeclaration(Zone* zone, VariableProxy* proxy, Scope* scope, int pos)
-      : Declaration(zone, proxy, LET, scope, pos) {}
-};
-
-
 class Module : public AstNode {
  public:
   ModuleDescriptor* descriptor() const { return descriptor_; }
@@ -3117,13 +3102,6 @@ class AstNodeFactory final BASE_EMBEDDED {
         parser_zone_, proxy, import_name, module_specifier, scope, pos);
   }
 
-  ExportDeclaration* NewExportDeclaration(VariableProxy* proxy,
-                                          Scope* scope,
-                                          int pos) {
-    return new (parser_zone_)
-        ExportDeclaration(parser_zone_, proxy, scope, pos);
-  }
-
   Block* NewBlock(ZoneList<const AstRawString*>* labels, int capacity,
                   bool ignore_completion_value, int pos) {
     return new (local_zone_)