Add InsertInstructionAfter in HBasicBlock.

Change-Id: I56e4e6edb39d1aab747877b7e517e94f0393f296
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index b89487f..cba64c5 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -567,7 +567,9 @@
   void DisconnectFromAll();
 
   void AddInstruction(HInstruction* instruction);
+  // Insert `instruction` before/after an existing instruction `cursor`.
   void InsertInstructionBefore(HInstruction* instruction, HInstruction* cursor);
+  void InsertInstructionAfter(HInstruction* instruction, HInstruction* cursor);
   // Replace instruction `initial` with `replacement` within this block.
   void ReplaceAndRemoveInstructionWith(HInstruction* initial,
                                        HInstruction* replacement);