Use fast_sqrt instead of std::sqrt in simulators.

src/ppc/simulator-ppc.cc

 // Copyright 2014 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 <stdarg.h>
 #include <stdlib.h>
 #include <cmath>
 
 #include "src/v8.h"
 
@@ skipping 2595 matching lines @@
       double fra_val = get_double_from_d_register(fra);
       double frb_val = get_double_from_d_register(frb);
       double frt_val = fra_val + frb_val;
       set_d_register_from_double(frt, frt_val);
       return;
     }
     case FSQRT: {
       int frt = instr->RTValue();
       int frb = instr->RBValue();
       double frb_val = get_double_from_d_register(frb);
-      double frt_val = std::sqrt(frb_val);
+      double frt_val = fast_sqrt(frb_val);
       set_d_register_from_double(frt, frt_val);
       return;
     }
     case FSEL: {
       int frt = instr->RTValue();
       int fra = instr->RAValue();
       int frb = instr->RBValue();
       int frc = instr->RCValue();
       double fra_val = get_double_from_d_register(fra);
       double frb_val = get_double_from_d_register(frb);
@@ skipping 1167 matching lines @@
   uintptr_t* stack_slot = reinterpret_cast<uintptr_t*>(current_sp);
   uintptr_t address = *stack_slot;
   set_register(sp, current_sp + sizeof(uintptr_t));
   return address;
 }
 }
 }  // namespace v8::internal
 
 #endif  // USE_SIMULATOR
 #endif  // V8_TARGET_ARCH_PPC