Provide a helper to generate multiple Lithium instructions for one Hydrogen instruction.

src/ia32/lithium-ia32.h

Index: src/ia32/lithium-ia32.h
diff --git a/src/ia32/lithium-ia32.h b/src/ia32/lithium-ia32.h
index 6cfe3e17f6f6937690d7cbcc3fcebe6e89a6bfe3..aeb1ab7025a26bda94fb08dff4c9dadbcc74b313 100644
--- a/src/ia32/lithium-ia32.h
+++ b/src/ia32/lithium-ia32.h
@@ -2831,6 +2831,7 @@ class LChunkBuilder V8_FINAL : public LChunkBuilderBase {
       CanDeoptimize can_deoptimize = CANNOT_DEOPTIMIZE_EAGERLY);
 
   void VisitInstruction(HInstruction* current);
+  void CheckAndAddInstruction(LInstruction* instr, HInstruction* current);
 
   void DoBasicBlock(HBasicBlock* block, HBasicBlock* next_block);
   LInstruction* DoShift(Token::Value op, HBitwiseBinaryOperation* instr);