Reapply "Lazy deopt without code patching."

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index 908f0f29a47a32aaec4dc8f7e132ccf6b18d97c3..79b0bdba3f47aa5cfcd587bf5abe0fee218d9348 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -813,6 +813,7 @@ Isolate::Isolate(const Dart_IsolateFlags& api_flags)
       gc_prologue_callback_(NULL),
       gc_epilogue_callback_(NULL),
       defer_finalization_count_(0),
+      pending_deopts_(new MallocGrowableArray<PendingLazyDeopt>),
       deopt_context_(NULL),
       is_service_isolate_(false),
       stacktrace_(NULL),
@@ -878,6 +879,8 @@ Isolate::~Isolate() {
   constant_canonicalization_mutex_ = NULL;
   delete megamorphic_lookup_mutex_;
   megamorphic_lookup_mutex_ = NULL;
+  delete pending_deopts_;
+  pending_deopts_ = NULL;
   delete message_handler_;
   message_handler_ = NULL;  // Fail fast if we send messages to a dead isolate.
   ASSERT(deopt_context_ == NULL);  // No deopt in progress when isolate deleted.