Remove synthetic unresolved variables from async/await desugaring

src/parsing/parser.h

Index: src/parsing/parser.h
diff --git a/src/parsing/parser.h b/src/parsing/parser.h
index 9019eb34e9395bcb073d7fa215af9021cfc4ff39..b1cbe2ce3079a2b1e2905e50162c0f0e1ca2ba4a 100644
--- a/src/parsing/parser.h
+++ b/src/parsing/parser.h
@@ -143,7 +143,7 @@ struct ParserTypes<Parser> {
   typedef ParserBase<Parser> Base;
   typedef Parser Impl;
 
-  typedef Variable GeneratorVariable;
+  typedef v8::internal::Variable Variable;
 
   // Return types for traversing functions.
   typedef const AstRawString* Identifier;
@@ -583,8 +583,7 @@ class Parser : public ParserBase<Parser> {
   Expression* BuildCreateJSGeneratorObject(int pos, FunctionKind kind);
   Expression* BuildResolvePromise(Expression* value, int pos);
   Expression* BuildRejectPromise(Expression* value, int pos);
-  VariableProxy* BuildDotPromise();
-  VariableProxy* BuildDotDebugIsActive();
+  Variable* PromiseVariable();
 
   // Generic AST generator for throwing errors from compiled code.
   Expression* NewThrowError(Runtime::FunctionId function_id,