MIPS: Never hchange nan-hole to hole or hole to nan-hole. Only allow changing hole to nan if all us…

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index 23f48a7709d06096bc298574a67aac188121b2c8..861e65dfbb1bb66bc8f94fb7bcf333515cd56dfd 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -1652,6 +1652,13 @@ LInstruction* LChunkBuilder::DoCompareObjectEqAndBranch(
 }
 
 
+LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
+    HCompareHoleAndBranch* instr) {
+  LOperand* object = UseRegisterAtStart(instr->object());
+  return new(zone()) LCmpHoleAndBranch(object);
+}
+
+
 LInstruction* LChunkBuilder::DoIsObjectAndBranch(HIsObjectAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());
   LOperand* temp = TempRegister();