Lazy deopt:

runtime/vm/stack_frame.h

Index: runtime/vm/stack_frame.h
diff --git a/runtime/vm/stack_frame.h b/runtime/vm/stack_frame.h
index 9cc7bd573ef68598eff00ab0799f337509b6b4cc..df105ab55b7d1b1bdb27d171067e2d0bf000ce56 100644
--- a/runtime/vm/stack_frame.h
+++ b/runtime/vm/stack_frame.h
@@ -51,6 +51,24 @@ class StackFrame : public ValueObject {
     return 0;
   }
 
+  uword IsMarkedForLazyDeopt() const {
+    uword raw_pc = *reinterpret_cast<uword*>(
+        sp() + (kSavedPcSlotFromSp * kWordSize));
+    return raw_pc == StubCode::DeoptimizeLazyFromReturn_entry()->EntryPoint();
+  }
+  void MarkForLazyDeopt() {
+    set_pc(StubCode::DeoptimizeLazyFromReturn_entry()->EntryPoint());
+  }
+  void UnmarkForLazyDeopt() {
+    // If this frame was marked for lazy deopt, pc_ was computed to be the
+    // original return address using the pending deopts table in GetCallerPc.
+    // Write this value back into the frame.
+    uword original_pc = pc();
+    ASSERT(original_pc !=
+           StubCode::DeoptimizeLazyFromReturn_entry()->EntryPoint());
+    set_pc(original_pc);
+  }
+
   void set_pc(uword value) {
     *reinterpret_cast<uword*>(sp() + (kSavedPcSlotFromSp * kWordSize)) = value;
     pc_ = value;
@@ -362,6 +380,11 @@ class InlinedFunctionsIterator : public ValueObject {
 };
 
 
+#if defined(DEBUG)
+void ValidateFrames();
+#endif
+
+
 #if !defined(TARGET_ARCH_DBC)
 DART_FORCE_INLINE static intptr_t LocalVarIndex(intptr_t fp_offset,
                                                 intptr_t var_index) {