Reapply "Lazy deopt without code patching."

runtime/vm/flow_graph_compiler.cc

Index: runtime/vm/flow_graph_compiler.cc
diff --git a/runtime/vm/flow_graph_compiler.cc b/runtime/vm/flow_graph_compiler.cc
index 5a22e4bd4f3354fbf45f5028b41d6e23db63cf79..e4f461e6408809306ad2e8c3f59e579681dffaad 100644
--- a/runtime/vm/flow_graph_compiler.cc
+++ b/runtime/vm/flow_graph_compiler.cc
@@ -225,8 +225,6 @@ FlowGraphCompiler::FlowGraphCompiler(
                 LookupClass(Symbols::List()))),
         parallel_move_resolver_(this),
         pending_deoptimization_env_(NULL),
-        lazy_deopt_return_pc_offset_(Code::kInvalidPc),
-        lazy_deopt_throw_pc_offset_(Code::kInvalidPc),
         deopt_id_to_ic_data_(NULL),
         edge_counters_array_(Array::ZoneHandle()),
         inlined_code_intervals_(Array::ZoneHandle(Object::empty_array().raw())),
@@ -1031,8 +1029,6 @@ void FlowGraphCompiler::FinalizePcDescriptors(const Code& code) {
       pc_descriptors_list_->FinalizePcDescriptors(code.PayloadStart()));
   if (!is_optimizing_) descriptors.Verify(parsed_function_.function());
   code.set_pc_descriptors(descriptors);
-  code.set_lazy_deopt_return_pc_offset(lazy_deopt_return_pc_offset_);
-  code.set_lazy_deopt_throw_pc_offset(lazy_deopt_throw_pc_offset_);
 }