Revert of [builtins] Introduce proper Float64Exp operator.

src/crankshaft/hydrogen-instructions.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/crankshaft/hydrogen-instructions.h"
 
 #include "src/base/bits.h"
 #include "src/base/ieee754.h"
 #include "src/base/safe_math.h"
 #include "src/crankshaft/hydrogen-infer-representation.h"
@@ skipping 3405 matching lines @@
           return H_CONSTANT_DOUBLE(d);
         case kMathClz32:
           return H_CONSTANT_INT(32);
         default:
           UNREACHABLE();
           break;
       }
     }
     switch (op) {
       case kMathExp:
-        return H_CONSTANT_DOUBLE(base::ieee754::exp(d));
+        lazily_initialize_fast_exp(isolate);
+        return H_CONSTANT_DOUBLE(fast_exp(d, isolate));
       case kMathLog:
         return H_CONSTANT_DOUBLE(base::ieee754::log(d));
       case kMathSqrt:
         lazily_initialize_fast_sqrt(isolate);
         return H_CONSTANT_DOUBLE(fast_sqrt(d, isolate));
       case kMathPowHalf:
         return H_CONSTANT_DOUBLE(power_double_double(d, 0.5));
       case kMathAbs:
         return H_CONSTANT_DOUBLE((d >= 0.0) ? d + 0.0 : -d);
       case kMathRound:
@@ skipping 594 matching lines @@
     case HObjectAccess::kExternalMemory:
       os << "[external-memory]";
       break;
   }
 
   return os << "@" << access.offset();
 }
 
 }  // namespace internal
 }  // namespace v8