First stab at try-catch and try-finally in TurboFan.

src/compiler/graph-builder.h

Index: src/compiler/graph-builder.h
diff --git a/src/compiler/graph-builder.h b/src/compiler/graph-builder.h
index 8374675ab62f9ea5b842a87a3cf4e301cad95d8b..62f1dde9730c1a0eded68cd83dc689bba56a4d2b 100644
--- a/src/compiler/graph-builder.h
+++ b/src/compiler/graph-builder.h
@@ -235,6 +235,10 @@ class StructuredGraphBuilder::Environment : public ZoneObject {
   CommonOperatorBuilder* common() { return builder_->common(); }
   NodeVector* values() { return &values_; }
 
+  // Friends using the values vector.

[titzer, 2015/02/02 09:47:29]

What if instead of friending, you added public methods Push() and Pop()?

This will get easier when we put AstGraphBuilder and GraphBuilder back together
again.

[Michael Starzinger, 2015/02/02 14:47:41]

Acknowledged. Yeah, well, we could do that if StructuredGraphBuilder weren't
abstractified out. I placed a TODO here.

[Michael Starzinger, 2015/02/03 09:35:18]

Done. Now possible after rebasing.

+  friend class TryCatchBuilder;
+  friend class TryFinallyBuilder;
+
   // Prepare environment to be used as loop header.
   void PrepareForLoop(BitVector* assigned, bool is_osr = false);