[turbofan] Introduce Float64Pow and NumberPow operators.

src/crankshaft/hydrogen.cc

Index: src/crankshaft/hydrogen.cc
diff --git a/src/crankshaft/hydrogen.cc b/src/crankshaft/hydrogen.cc
index 8a2b8de3618d43ad9942a61b5574a863a44317aa..8d2d2146247f7b93f5387cf8625d8fe7da0f3a92 100644
--- a/src/crankshaft/hydrogen.cc
+++ b/src/crankshaft/hydrogen.cc
@@ -12808,18 +12808,6 @@ void HOptimizedGraphBuilder::GenerateCall(CallRuntime* call) {
 }
 
 
-// Fast call to math functions.
-void HOptimizedGraphBuilder::GenerateMathPow(CallRuntime* call) {
-  DCHECK_EQ(2, call->arguments()->length());
-  CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
-  CHECK_ALIVE(VisitForValue(call->arguments()->at(1)));
-  HValue* right = Pop();
-  HValue* left = Pop();
-  HInstruction* result = NewUncasted<HPower>(left, right);
-  return ast_context()->ReturnInstruction(result, call->id());
-}
-
-
 void HOptimizedGraphBuilder::GenerateFixedArrayGet(CallRuntime* call) {
   DCHECK(call->arguments()->length() == 2);
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));