Move deopt_id and related helpers/definitions from Isolate to Thread

runtime/vm/deopt_instructions.cc

Index: runtime/vm/deopt_instructions.cc
diff --git a/runtime/vm/deopt_instructions.cc b/runtime/vm/deopt_instructions.cc
index 79f08d8f01e1a354a6edb0827ed74d3bc0231ce5..134d85cbb1a4ac2681752c4145cf7127ace7b12d 100644
--- a/runtime/vm/deopt_instructions.cc
+++ b/runtime/vm/deopt_instructions.cc
@@ -826,7 +826,7 @@ uword DeoptInstr::GetRetAddress(DeoptInstr* instr,
       static_cast<DeoptRetAddressInstr*>(instr);
   // The following assert may trigger when displaying a backtrace
   // from the simulator.
-  ASSERT(Isolate::IsDeoptAfter(ret_address_instr->deopt_id()));
+  ASSERT(Thread::IsDeoptAfter(ret_address_instr->deopt_id()));
   ASSERT(!object_table.IsNull());
   Thread* thread = Thread::Current();
   Zone* zone = thread->zone();