Remove HCheckSmi, LCheckSmi and rename LCheckSmiAndReturn to LCheckSmi.

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index a0037770f1f195dc62d79bc18b4c6bb2b1d9e8cf..d7ac279a4cd852d27b4232c5613712169df5f9d3 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -1833,8 +1833,7 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
       if (val->type().IsSmi()) {
         return DefineSameAsFirst(new(zone()) LDummyUse(value));
       }
-      return AssignEnvironment(
-          DefineSameAsFirst(new(zone()) LCheckSmiAndReturn(value)));
+      return AssignEnvironment(DefineSameAsFirst(new(zone()) LCheckSmi(value)));
     } else {
       ASSERT(to.IsInteger32());
       LOperand* value = UseRegister(instr->value());
@@ -1928,12 +1927,6 @@ LInstruction* LChunkBuilder::DoCheckPrototypeMaps(HCheckPrototypeMaps* instr) {
 }
 
 
-LInstruction* LChunkBuilder::DoCheckSmi(HCheckSmi* instr) {
-  LOperand* value = UseRegisterAtStart(instr->value());
-  return AssignEnvironment(new(zone()) LCheckSmi(value));
-}
-
-
 LInstruction* LChunkBuilder::DoCheckFunction(HCheckFunction* instr) {
   LOperand* value = UseRegisterAtStart(instr->value());
   return AssignEnvironment(new(zone()) LCheckFunction(value));