Revert of [builtins] Introduce proper Float64Exp operator.

src/codegen.cc

 // 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.
 
 #include "src/codegen.h"
 
 #if defined(V8_OS_AIX)
 #include <fenv.h>  // NOLINT(build/c++11)
 #endif
 #include "src/ast/prettyprinter.h"
@@ skipping 42 matching lines @@
     if (!fast_##name##_function) fast_##name##_function = std_##name;    \
   }                                                                      \
   void lazily_initialize_fast_##name(Isolate* isolate) {                 \
     if (!fast_##name##_function) init_fast_##name##_function(isolate);   \
   }                                                                      \
   double fast_##name(double x, Isolate* isolate) {                       \
     return (*fast_##name##_function)(x, isolate);                        \
   }
 
 UNARY_MATH_FUNCTION(sqrt, CreateSqrtFunction)
+UNARY_MATH_FUNCTION(exp, CreateExpFunction)
 
 #undef UNARY_MATH_FUNCTION
 
 
 #define __ ACCESS_MASM(masm_)
 
 #ifdef DEBUG
 
 Comment::Comment(MacroAssembler* masm, const char* msg)
     : masm_(masm), msg_(msg) {
@@ skipping 121 matching lines @@
       os << "source_position = " << shared->start_position() << "\n";
     }
     code->Disassemble(debug_name.get(), os);
     os << "--- End code ---\n";
   }
 #endif  // ENABLE_DISASSEMBLER
 }
 
 }  // namespace internal
 }  // namespace v8