Add Schedule::InsertBranch to fuse control flow graphs.

src/compiler/schedule.h

Index: src/compiler/schedule.h
diff --git a/src/compiler/schedule.h b/src/compiler/schedule.h
index 5ff554f821e6545f5666e0b3b5b0325f030885b9..fbb00b0ee8d56aa590fb7d403e84e82e09d38fa8 100644
--- a/src/compiler/schedule.h
+++ b/src/compiler/schedule.h
@@ -95,6 +95,7 @@ class BasicBlock FINAL : public ZoneObject {
   }
   size_t PredecessorCount() const { return predecessors_.size(); }
   BasicBlock* PredecessorAt(size_t index) { return predecessors_[index]; }
+  void ClearPredecessors() { predecessors_.clear(); }
   void AddPredecessor(BasicBlock* predecessor);
 
   typedef ZoneVector<BasicBlock*> Successors;
@@ -108,6 +109,7 @@ class BasicBlock FINAL : public ZoneObject {
   }
   size_t SuccessorCount() const { return successors_.size(); }
   BasicBlock* SuccessorAt(size_t index) { return successors_[index]; }
+  void ClearSuccessors() { successors_.clear(); }
   void AddSuccessor(BasicBlock* successor);
 
   // Nodes in the basic block.
@@ -240,7 +242,13 @@ class Schedule FINAL : public ZoneObject {
   // BasicBlock building: add a throw at the end of {block}.
   void AddThrow(BasicBlock* block, Node* input);
 
+  // BasicBlock mutation: insert a branch into the end of {block}.
+  void InsertBranch(BasicBlock* block, BasicBlock* end, Node* branch,
+                    BasicBlock* tblock, BasicBlock* fblock);
+
+  // Exposed publicly for testing only.

[Jarin, 2014/10/24 13:21:19]

Could you then move this to the private section and create forwarding methods
that end with ForTesting? (So that it is really checked that we only use this
from tests.)

[Michael Starzinger, 2014/10/24 13:44:05]

Done. Good idea!

   void AddSuccessor(BasicBlock* block, BasicBlock* succ);
+  void MoveSuccessors(BasicBlock* from, BasicBlock* to);
 
   BasicBlockVector* rpo_order() { return &rpo_order_; }
   const BasicBlockVector* rpo_order() const { return &rpo_order_; }