Lazy deopt without code patching.

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 268ca4a9998819930ed8b30b3cb92ef2bab75a7e..69adea4bfbd5119a24e157e053595aea460afbde 100644
--- a/runtime/vm/stack_frame.h
+++ b/runtime/vm/stack_frame.h
@@ -53,6 +53,7 @@ class StackFrame : public ValueObject {
 
   void set_pc(uword value) {
     *reinterpret_cast<uword*>(sp() + (kSavedPcSlotFromSp * kWordSize)) = value;
+    pc_ = value;
   }
 
   void set_pc_marker(RawCode* code) {
@@ -110,8 +111,21 @@ class StackFrame : public ValueObject {
   }
 
   uword GetCallerPc() const {
-    return *(reinterpret_cast<uword*>(
+    uword raw_pc = *(reinterpret_cast<uword*>(
         fp() + (kSavedCallerPcSlotFromFp * kWordSize)));
+    ASSERT(raw_pc != StubCode::DeoptimizeLazyFromThrow_entry()->EntryPoint());
+    if (raw_pc == StubCode::DeoptimizeLazyFromReturn_entry()->EntryPoint()) {
+      uword fp = GetCallerFp();
+      MallocGrowableArray<PendingLazyDeopt>* pending_deopts =
+          isolate()->pending_deopts();
+      for (intptr_t i = 0; i < pending_deopts->length(); i++) {
+        if ((*pending_deopts)[i].fp() == fp) {
+          return (*pending_deopts)[i].pc();
+        }
+      }
+      UNREACHABLE();
+    }
+    return raw_pc;
   }
 
   uword fp_;