Don't inline functions that the parser decides shouldn't be inlined.

runtime/vm/flow_graph_inliner.cc

 // Copyright (c) 2013, 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.
 #if !defined(DART_PRECOMPILED_RUNTIME)
 #include "vm/flow_graph_inliner.h"
 
 #include "vm/aot_optimizer.h"
 #include "vm/precompiler.h"
 #include "vm/block_scheduler.h"
 #include "vm/branch_optimizer.h"
@@ skipping 762 matching lines @@
           Compiler::AbortBackgroundCompilation(Thread::kNoDeoptId,
                                                "ICData cleared while inlining");
         }
 
         // Parse the callee function.
         bool in_cache;
         ParsedFunction* parsed_function;
         {
           CSTAT_TIMER_SCOPE(thread(), graphinliner_parse_timer);
           parsed_function = GetParsedFunction(function, &in_cache);
+          if (!function.CanBeInlined()) {
+            // As a side effect of parsing the function, it may be marked

[Kevin Millikin (Google), 2017/02/24 14:32:28]

We already know whether the function is async or async* (when we created it), so
we shouldn't need to parse it.  I suggest marking async and async* functions not
inlinable at the same time that their modifier is set and letting the earlier
CanBeInlined() test in this method catch them without going through all the
other work.

+            // as not inlinable. This happens for async and async* functions
+            // when causal stack traces are being tracked.
+            return false;
+          }
         }
 
+
         // Build the callee graph.
         InlineExitCollector* exit_collector =
             new (Z) InlineExitCollector(caller_graph_, call);
         FlowGraph* callee_graph;
         if (UseKernelFrontEndFor(parsed_function)) {
           kernel::TreeNode* node = static_cast<kernel::TreeNode*>(
               parsed_function->function().kernel_function());
 
           kernel::FlowGraphBuilder builder(
               node, parsed_function, *ic_data_array, exit_collector,
@@ skipping 2836 matching lines @@
     }
 
     default:
       return false;
   }
 }
 
 
 }  // namespace dart
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)