In code comments print also deopt reason for deoptimization stubs.

runtime/vm/flow_graph_compiler.h

 // 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.
 
 #ifndef VM_FLOW_GRAPH_COMPILER_H_
 #define VM_FLOW_GRAPH_COMPILER_H_
 
 #include "vm/allocation.h"
 #include "vm/assembler.h"
 #include "vm/code_descriptors.h"
@@ skipping 147 matching lines @@
                             Environment* deopt_env)
       : CompilerDeoptInfo(deopt_id, reason, deopt_env), entry_label_() {
     ASSERT(reason != ICData::kDeoptAtCall);
   }
 
   Label* entry_label() { return &entry_label_; }
 
   // Implementation is in architecture specific file.
   virtual void GenerateCode(FlowGraphCompiler* compiler, intptr_t stub_ix);
 
+  const char* Name() const {
+    const char* kFormat = "Deopt stub for id %d, reason: %s";
+    const intptr_t len = OS::SNPrint(NULL, 0, kFormat,
+        deopt_id(), DeoptReasonToCString(reason())) + 1;
+    char* chars = Isolate::Current()->current_zone()->Alloc<char>(len);
+    OS::SNPrint(chars, len, kFormat,
+        deopt_id(), DeoptReasonToCString(reason()));
+    return chars;
+  }
+
  private:
   Label entry_label_;
 
   DISALLOW_COPY_AND_ASSIGN(CompilerDeoptInfoWithStub);
 };
 
 
 class SlowPathCode : public ZoneAllocated {
  public:
   SlowPathCode() : entry_label_(), exit_label_() { }
@@ skipping 441 matching lines @@
   intptr_t lazy_deopt_pc_offset_;
 
   ZoneGrowableArray<const ICData*>* deopt_id_to_ic_data_;
 
   DISALLOW_COPY_AND_ASSIGN(FlowGraphCompiler);
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_COMPILER_H_