[ignition] Create the type feedback vector after bytecode generation

src/interpreter/bytecode-generator.cc

Index: src/interpreter/bytecode-generator.cc
diff --git a/src/interpreter/bytecode-generator.cc b/src/interpreter/bytecode-generator.cc
index 8c5942143c4021bd9c46f145228f0edbbfe63283..bcd7aa5205a784d456d82b9c6c56cecae4cb02ff 100644
--- a/src/interpreter/bytecode-generator.cc
+++ b/src/interpreter/bytecode-generator.cc
@@ -651,6 +651,14 @@ void BytecodeGenerator::AllocateDeferredConstants(Isolate* isolate) {
         array_literal->GetOrBuildConstantElements(isolate);
     builder()->InsertConstantPoolEntryAt(literal.second, constant_elements);
   }
+
+  // TODO(leszeks): ideally there would be no path to here where feedback
+  // metadata is previously created, and we could create it unconditionally.
+  // We should investigate again once FCG has shuffled off its mortal coil.
+  DCHECK(info()->has_shared_info());
+  TypeFeedbackMetadata::EnsureAllocated(

[Michael Starzinger, 2017/01/16 15:28:41]

Some follow-up questions:
1) Would it be possible to do this in FinalizeUnoptimizedCompilationJob instead?
2) And more importantly could we keep it in sync with FCG and also allocate it
just before unoptimized code is installed for FullCodegenCompilationJob?

[Leszek Swirski, 2017/01/16 16:28:03]

I'm hesitant, could this interact badly with --always-opt?

+      info()->isolate(), info()->shared_info(),
+      info()->literal()->feedback_vector_spec());
 }
 
 void BytecodeGenerator::GenerateBytecode(uintptr_t stack_limit) {