Don't duplicate ceiling() for every POSIX platform.

src/platform-posix.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 207 matching lines @@
   asm("int $3");
 #else
 #error Unsupported host architecture.
 #endif
 }
 
 
 // ----------------------------------------------------------------------------
 // Math functions
 
+double ceiling(double x) {
+  // Correct buggy 'ceil' on some systems (i.e. FreeBSD, OS X 10.5)
+  return (-1.0 < x && x < 0.0) ? -0.0 : ceil(x);
+}
+
+
 double modulo(double x, double y) {
   return fmod(x, y);
 }
 
 
 #define UNARY_MATH_FUNCTION(name, generator)             \
 static UnaryMathFunction fast_##name##_function = NULL;  \
 void init_fast_##name##_function() {                     \
   fast_##name##_function = generator;                    \
 }                                                        \
@@ skipping 716 matching lines @@
   return ntohl(value);
 }
 
 
 Socket* OS::CreateSocket() {
   return new POSIXSocket();
 }
 
 
 } }  // namespace v8::internal