remove unused openbsd std::isfinite and std::signbit implementations

Source/wtf/MathExtras.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 35 matching lines @@
 
 const double piOverTwoDouble = M_PI_2;
 const float piOverTwoFloat = static_cast<float>(M_PI_2);
 
 const double piOverFourDouble = M_PI_4;
 const float piOverFourFloat = static_cast<float>(M_PI_4);
 
 const double twoPiDouble = piDouble * 2.0;
 const float twoPiFloat = piFloat * 2.0f;
 
-#if OS(OPENBSD)
-
-namespace std {
-
-#ifndef isfinite
-inline bool isfinite(double x) { return finite(x); }
-#endif
-#ifndef signbit
-inline bool signbit(double x) { struct ieee_double *p = (struct ieee_double *)&x; return p->dbl_sign; }
-#endif
-
-} // namespace std
-
-#endif
-
 #if OS(ANDROID) || COMPILER(MSVC)
 // ANDROID and MSVC's math.h does not currently supply log2 or log2f.
 inline double log2(double num)
 {
     // This constant is roughly M_LN2, which is not provided by default on Windows and Android.
     return log(num) / 0.693147180559945309417232121458176568;
 }
 
 inline float log2f(float num)
 {
@@ skipping 270 matching lines @@
     if (i >> 2)
         log2 += 2, i >>= 2;
     if (i >> 1)
         log2 += 1;
     return log2;
 }
 
 } // namespace WTF
 
 #endif // #ifndef WTF_MathExtras_h