Fail early when re-entering code that has been patched for lazy deopt

src/a64/deoptimizer-a64.cc

Index: src/a64/deoptimizer-a64.cc
diff --git a/src/a64/deoptimizer-a64.cc b/src/a64/deoptimizer-a64.cc
index 660feb2394351f95d40eae6e39ec7d745a930f70..66e501aeeba27bc6144882b0891e724ae1ada455 100644
--- a/src/a64/deoptimizer-a64.cc
+++ b/src/a64/deoptimizer-a64.cc
@@ -50,6 +50,9 @@ void Deoptimizer::PatchCodeForDeoptimization(Isolate* isolate, Code* code) {
   // code patching below, and is not needed any more.
   code->InvalidateRelocation();
 
+  // TODO(jkummerow): if (FLAG_zap_code_space), make the code object's
+  // entry sequence unusable (see other architectures).
+
   // For each LLazyBailout instruction insert a call to the corresponding
   // deoptimization entry.
   DeoptimizationInputData* deopt_data =