[turbofan] Unify Math.floor / Math.ceil optimization.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 0456f60a370808c1417072e13a6f63cbf4971d4f..1c1375b06b8d84b4f55b6b92169ec3112e265e97 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -12046,6 +12046,15 @@ void HOptimizedGraphBuilder::GenerateMathPow(CallRuntime* call) {
 }
 
 
+void HOptimizedGraphBuilder::GenerateMathFloor(CallRuntime* call) {
+  DCHECK(call->arguments()->length() == 1);
+  CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
+  HValue* value = Pop();
+  HInstruction* result = NewUncasted<HUnaryMathOperation>(value, kMathFloor);
+  return ast_context()->ReturnInstruction(result, call->id());
+}
+
+
 void HOptimizedGraphBuilder::GenerateMathLogRT(CallRuntime* call) {
   DCHECK(call->arguments()->length() == 1);
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));