[compiler] Make feedback vector cope with flag changes.

src/compiler.cc

Index: src/compiler.cc
diff --git a/src/compiler.cc b/src/compiler.cc
index 7977bd04d3da23c6ef018fd343906bd241a27e86..d39738215056c644a4507f21393fda7ec5bd28b1 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -744,9 +744,11 @@ void EnsureFeedbackVector(CompilationInfo* info) {
   if (!info->has_shared_info()) return;
 
   // If no type feedback vector exists, we create one now. At this point the
-  // AstNumbering pass has already run. Note that we should reuse any existing
-  // feedback vector rather than creating a new one.
-  if (info->shared_info()->feedback_vector()->is_empty()) {
+  // AstNumbering pass has already run. Note the snapshot can contain outdated
+  // vectors for a different configuration, hence we also recreate a new vector
+  // when the function is not compiled (i.e. no code was serialized).
+  if (info->shared_info()->feedback_vector()->is_empty() ||
+      !info->shared_info()->is_compiled()) {
     Handle<TypeFeedbackMetadata> feedback_metadata = TypeFeedbackMetadata::New(
         info->isolate(), info->literal()->feedback_vector_spec());
     Handle<TypeFeedbackVector> feedback_vector =