Make MathFloorOfDiv optimization trigger more often

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 57a8b2e2974396d006c985f03b227d10ff0cd5b5..de3ab2f6ff97c74db522ad2d12939dc3309749a7 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -1386,19 +1386,6 @@ LInstruction* LChunkBuilder::DoDiv(HDiv* instr) {
 }
 
 
-HValue* LChunkBuilder::SimplifiedDividendForMathFloorOfDiv(HValue* dividend) {
-  // A value with an integer representation does not need to be transformed.
-  if (dividend->representation().IsInteger32()) {
-    return dividend;
-  // A change from an integer32 can be replaced by the integer32 value.
-  } else if (dividend->IsChange() &&
-      HChange::cast(dividend)->from().IsInteger32()) {
-    return HChange::cast(dividend)->value();
-  }
-  return NULL;
-}
-
-
 HValue* LChunkBuilder::SimplifiedDivisorForMathFloorOfDiv(HValue* divisor) {
   if (divisor->IsConstant() &&
       HConstant::cast(divisor)->HasInteger32Value()) {