Refactor lithium CheckSmi instruction into two separate instructions CheckSmi...

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
===================================================================
--- src/x64/lithium-x64.cc	(revision 7203)
+++ src/x64/lithium-x64.cc	(working copy)
@@ -1658,7 +1658,7 @@
 
 LInstruction* LChunkBuilder::DoCheckNonSmi(HCheckNonSmi* instr) {
   LOperand* value = UseRegisterAtStart(instr->value());
-  return AssignEnvironment(new LCheckSmi(value, zero));
+  return AssignEnvironment(new LCheckNonSmi(value));
 }
 
 
@@ -1678,7 +1678,7 @@
 
 LInstruction* LChunkBuilder::DoCheckSmi(HCheckSmi* instr) {
   LOperand* value = UseRegisterAtStart(instr->value());
-  return AssignEnvironment(new LCheckSmi(value, not_zero));
+  return AssignEnvironment(new LCheckSmi(value));
 }