Revert "Mark async and generator functions as debuggable, so their frames are visible for return ty…

runtime/vm/parser.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/parser.h"
 
 #include "lib/invocation_mirror.h"
 #include "platform/utils.h"
 #include "vm/ast_transformer.h"
 #include "vm/bootstrap.h"
@@ skipping 3163 matching lines @@
     // Don't add a modifier to the closure representing the body of
     // the asynchronous function or generator.
     func.set_modifier(func_modifier);
   }
 
   OpenBlock();  // Open a nested scope for the outermost function block.
 
   Function& generated_body_closure = Function::ZoneHandle(Z);
   if (func.IsAsyncFunction()) {
     ASSERT(!func.is_generated_body());
-    // Must show frame for checked mode return type error.
-    ASSERT(func.is_debuggable());
+    // The code of an async function is synthesized. Disable debugging.
+    func.set_is_debuggable(false);
     generated_body_closure = OpenAsyncFunction(func.token_pos());
   } else if (func.IsAsyncClosure()) {
     // The closure containing the body of an async function is debuggable.
     ASSERT(func.is_debuggable());
     OpenAsyncClosure();
   } else if (func.IsSyncGenerator()) {
-    // Must show frame for checked mode return type error.
-    ASSERT(func.is_debuggable());
+    // The code of a sync generator is synthesized. Disable debugging.
+    func.set_is_debuggable(false);
     generated_body_closure = OpenSyncGeneratorFunction(func.token_pos());
   } else if (func.IsSyncGenClosure()) {
     // The closure containing the body of a sync generator is debuggable.
     ASSERT(func.is_debuggable());
     async_temp_scope_ = current_block_->scope;
   } else if (func.IsAsyncGenerator()) {
-    // Must show frame for checked mode return type error.
-    ASSERT(func.is_debuggable());
+    func.set_is_debuggable(false);
     generated_body_closure = OpenAsyncGeneratorFunction(func.token_pos());
   } else if (func.IsAsyncGenClosure()) {
     // The closure containing the body of an async* function is debuggable.
     ASSERT(func.is_debuggable());
     OpenAsyncGeneratorClosure();
   }
 
   BoolScope allow_await(&this->await_is_keyword_,
                         func.IsAsyncOrGenerator() || func.is_generated_body());
   intptr_t end_token_pos = 0;
@@ skipping 10010 matching lines @@
 void Parser::SkipQualIdent() {
   ASSERT(IsIdentifier());
   ConsumeToken();
   if (CurrentToken() == Token::kPERIOD) {
     ConsumeToken();  // Consume the kPERIOD token.
     ExpectIdentifier("identifier expected after '.'");
   }
 }
 
 }  // namespace dart