Remove unused pc-descriptor kind kReturn.

runtime/vm/flow_graph_builder.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/flow_graph_builder.h"
 
 #include "lib/invocation_mirror.h"
 #include "vm/ast_printer.h"
 #include "vm/bit_vector.h"
 #include "vm/class_finalizer.h"
@@ skipping 992 matching lines @@
 
   // Call to stub that checks whether the debugger is in single
   // step mode. This call must happen before the contexts are
   // unchained so that captured variables can be inspected.
   // No debugger check is done in native functions or for return
   // statements for which there is no associated source position.
   const Function& function = owner()->parsed_function()->function();
   if ((node->token_pos() != Scanner::kNoSourcePos) &&
       !function.is_native() && FLAG_enable_debugger) {
     AddInstruction(new DebugStepCheckInstr(node->token_pos(),
-                                           PcDescriptors::kReturn));
+                                           PcDescriptors::kRuntimeCall));
   }
 
   if (FLAG_enable_type_checks) {
     const bool is_implicit_dynamic_getter =
         (!function.is_static() &&
         ((function.kind() == RawFunction::kImplicitGetter) ||
          (function.kind() == RawFunction::kImplicitStaticFinalGetter)));
     // Implicit getters do not need a type check at return, unless they compute
     // the initial value of a static field.
     // The body of a constructor cannot modify the type of the
@@ skipping 2924 matching lines @@
   Report::MessageF(Report::kBailout,
                    Script::Handle(function.script()),
                    function.token_pos(),
                    "FlowGraphBuilder Bailout: %s %s",
                    String::Handle(function.name()).ToCString(),
                    reason);
   UNREACHABLE();
 }
 
 }  // namespace dart