platform: fix build on SmartOS

src/base/platform/platform-solaris.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.
 
 // Platform-specific code for Solaris 10 goes here. For the POSIX-compatible
 // parts, the implementation is in platform-posix.cc.
 
 #ifdef __sparc
 # error "V8 does not support the SPARC CPU architecture."
 #endif
@@ skipping 13 matching lines @@
 #include <unistd.h>  // getpagesize(), usleep()
 
 #include <cmath>
 
 #undef MAP_TYPE
 
 #include "src/base/macros.h"
 #include "src/base/platform/platform.h"
 
 
-// It seems there is a bug in some Solaris distributions (experienced in
-// SunOS 5.10 Generic_141445-09) which make it difficult or impossible to
-// access signbit() despite the availability of other C99 math functions.
-#ifndef signbit
-namespace std {
-// Test sign - usually defined in math.h
-int signbit(double x) {
-  // We need to take care of the special case of both positive and negative
-  // versions of zero.
-  if (x == 0) {
-    return fpclass(x) & FP_NZERO;
-  } else {
-    // This won't detect negative NaN but that should be okay since we don't
-    // assume that behavior.
-    return x < 0;
-  }
-}
-}  // namespace std
-#endif  // signbit
-
 namespace v8 {
 namespace base {
 
 
 const char* OS::LocalTimezone(double time, TimezoneCache* cache) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(std::floor(time/msPerSecond));
   struct tm* t = localtime(&tv);
   if (NULL == t) return "";
   return tzname[0];  // The location of the timezone string on Solaris.
@@ skipping 206 matching lines @@
   return munmap(base, size) == 0;
 }
 
 
 bool VirtualMemory::HasLazyCommits() {
   // TODO(alph): implement for the platform.
   return false;
 }
 
 } }  // namespace v8::base