[builtins] support exception handling in TFJ builtins

src/frames.cc

Index: src/frames.cc
diff --git a/src/frames.cc b/src/frames.cc
index 83b8d83c74c9f090eb5e3282dfb81ae44b31222e..fd996e16bb205630d97301c58e35418459dcba0d 100644
--- a/src/frames.cc
+++ b/src/frames.cc
@@ -879,6 +879,20 @@ Code* StubFrame::unchecked_code() const {
   return static_cast<Code*>(isolate()->FindCodeObject(pc()));
 }
 
+int StubFrame::LookupExceptionHandlerInTable(

[caitp, 2016/08/19 14:30:09]

seems to be unnecessary, only seemed to come up due to the tests generating stub
code rather than JS frames.

+    int* stack_slots, HandlerTable::CatchPrediction* prediction) {
+  DCHECK_NULL(prediction);
+  Code* code = LookupCode();
+
+  // Only support catch handlers in TFJ builtins.
+  if (!code->is_turbofanned()) return -1;
+  if (code->kind() != Code::BUILTIN) return -1;
+
+  HandlerTable* table = HandlerTable::cast(code->handler_table());
+  int pc_offset = static_cast<int>(pc() - code->entry());
+  if (stack_slots) *stack_slots = code->stack_slots();
+  return table->LookupReturn(pc_offset);
+}
 
 Address StubFrame::GetCallerStackPointer() const {
   return fp() + ExitFrameConstants::kCallerSPOffset;