[builtins] support exception handling in TFJ builtins

src/compiler/raw-machine-assembler.h

Index: src/compiler/raw-machine-assembler.h
diff --git a/src/compiler/raw-machine-assembler.h b/src/compiler/raw-machine-assembler.h
index f1bc3d789762eb3bd0338e4445c37310dbe5dc0b..17bfcc1a71ac81eb7bb86f8e8a518260471299f7 100644
--- a/src/compiler/raw-machine-assembler.h
+++ b/src/compiler/raw-machine-assembler.h
@@ -748,6 +748,7 @@ class RawMachineAssembler {
   void Goto(RawMachineLabel* label);
   void Branch(Node* condition, RawMachineLabel* true_val,
               RawMachineLabel* false_val);
+  void BranchIfException(Node* node, RawMachineLabel* if_exception);

[caitp, 2016/08/18 03:08:57]

I very much prefer a separate method vs adding optional if_exception Labels to
the millions of operations that the various Assemblers can perform.

   void Switch(Node* index, RawMachineLabel* default_label,
               const int32_t* case_values, RawMachineLabel** case_labels,
               size_t case_count);