Remember all deopt reasons in ic_data, not just the last one.

runtime/vm/stack_frame.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/stack_frame.h"
 
 #include "vm/assembler.h"
 #include "vm/deopt_instructions.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 379 matching lines @@
     num_materializations_(0),
     code_(Code::Handle(code.raw())),
     deopt_info_(DeoptInfo::Handle()),
     function_(Function::Handle()),
     pc_(pc),
     deopt_instructions_(),
     object_table_(Array::Handle()) {
   ASSERT(code_.is_optimized());
   ASSERT(pc_ != 0);
   ASSERT(code.ContainsInstructionAt(pc));
-  intptr_t deopt_reason = kDeoptUnknown;
+  ICData::DeoptReasonId deopt_reason = ICData::kDeoptUnknown;
   deopt_info_ = code_.GetDeoptInfoAtPc(pc, &deopt_reason);
   if (deopt_info_.IsNull()) {
     // This is the case when a call without deopt info in optimized code
     // throws an exception. (e.g. in the parameter copying prologue).
     // In that case there won't be any inlined frames.
     function_ = code_.function();
   } else {
     // Unpack deopt info into instructions (translate away suffixes).
     const Array& deopt_table = Array::Handle(code_.deopt_info_array());
     ASSERT(!deopt_table.IsNull());
@@ skipping 39 matching lines @@
     if (deopt_instr->kind() == DeoptInstr::kCallerFp) {
       return (index - num_materializations_);
     }
   }
   UNREACHABLE();
   return 0;
 }
 
 
 }  // namespace dart