We can throw an exception but we cannot deoptimize at a runtime call.

runtime/vm/il_printer.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/il_printer.h"
 
 #include "vm/intermediate_language.h"
 #include "vm/os.h"
 #include "vm/parser.h"
 
@@ skipping 519 matching lines @@
 }
 
 
 void ReturnInstr::PrintTo(BufferFormatter* f) const {
   f->Print("    %s:%d ", DebugName(), deopt_id());
   value()->PrintTo(f);
 }
 
 
 void ThrowInstr::PrintTo(BufferFormatter* f) const {
-  f->Print("    %s:%d ", DebugName(), deopt_id());
+  f->Print("    %s" , DebugName());
 }
 
 
 void ReThrowInstr::PrintTo(BufferFormatter* f) const {
-  f->Print("    %s:%d ", DebugName(), deopt_id());
+  f->Print("    %s ", DebugName());
 }
 
 
 void GotoInstr::PrintTo(BufferFormatter* f) const {
   if (HasParallelMove()) {
     parallel_move()->PrintTo(f);
   } else {
     f->Print("    ");
   }
   f->Print(" goto %d", successor()->block_id());
@@ skipping 216 matching lines @@
 }
 
 
 void ReturnInstr::PrintToVisualizer(BufferFormatter* f) const {
   f->Print("_ %s:%d ", DebugName(), deopt_id());
   value()->PrintTo(f);
 }
 
 
 void ThrowInstr::PrintToVisualizer(BufferFormatter* f) const {
-  f->Print("_ %s:%d ", DebugName(), deopt_id());
+  f->Print("_ %s ", DebugName());
 }
 
 
 void ReThrowInstr::PrintToVisualizer(BufferFormatter* f) const {
-  f->Print("_ %s:%d ", DebugName(), deopt_id());
+  f->Print("_ %s ", DebugName());
 }
 
 
 void GotoInstr::PrintToVisualizer(BufferFormatter* f) const {
   f->Print("_ goto B%d", successor()->block_id());
 }
 
 
 void BranchInstr::PrintToVisualizer(BufferFormatter* f) const {
   f->Print("_ %s ", DebugName());
@@ skipping 18 matching lines @@
     if ((locations_ != NULL) && !locations_[i].IsInvalid()) {
       f->Print(" [");
       locations_[i].PrintTo(f);
       f->Print("]");
     }
   }
   f->Print(" }");
 }
 
 }  // namespace dart