[turbofan] Introduce Float64Pow and NumberPow operators.

src/code-stubs.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_CODE_STUBS_H_
 #define V8_CODE_STUBS_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 #include "src/code-stub-assembler.h"
@@ skipping 1308 matching lines @@
  private:
   void GenerateCase(MacroAssembler* masm, ElementsKind kind);
 
   DEFINE_CALL_INTERFACE_DESCRIPTOR(ArrayNArgumentsConstructor);
   DEFINE_PLATFORM_CODE_STUB(InternalArrayConstructor, PlatformCodeStub);
 };
 
 
 class MathPowStub: public PlatformCodeStub {
  public:
-  enum ExponentType { INTEGER, DOUBLE, TAGGED, ON_STACK };
+  enum ExponentType { INTEGER, DOUBLE, TAGGED };
 
   MathPowStub(Isolate* isolate, ExponentType exponent_type)
       : PlatformCodeStub(isolate) {
     minor_key_ = ExponentTypeBits::encode(exponent_type);
   }
 
   CallInterfaceDescriptor GetCallInterfaceDescriptor() const override {
-    if (exponent_type() == ON_STACK) {
-      return OnStackArgsDescriptorBase::ForArgs(isolate(), 2);
-    } else if (exponent_type() == TAGGED) {
+    if (exponent_type() == TAGGED) {
       return MathPowTaggedDescriptor(isolate());
     } else if (exponent_type() == INTEGER) {
       return MathPowIntegerDescriptor(isolate());
     } else {
       // A CallInterfaceDescriptor doesn't specify double registers (yet).
       DCHECK_EQ(DOUBLE, exponent_type());
       return ContextOnlyDescriptor(isolate());
     }
   }
 
@@ skipping 1763 matching lines @@
 #undef DEFINE_HYDROGEN_CODE_STUB
 #undef DEFINE_CODE_STUB
 #undef DEFINE_CODE_STUB_BASE
 
 extern Representation RepresentationFromType(Type* type);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CODE_STUBS_H_