Fixing Math.pow(NaN, -0.0) == 1 on Windows.

src/assembler.cc

 // Copyright (c) 2011 Sun Microsystems 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:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 1106 matching lines @@
   // been done in generated code before bailing out here.
 #if !defined(V8_TARGET_ARCH_IA32)
   int y_int = static_cast<int>(y);
   if (y == y_int) {
     return power_double_int(x, y_int);  // Returns 1.0 for exponent 0.
   }
   if (!isinf(x)) {
     if (y == 0.5) return sqrt(x + 0.0);  // -0 must be converted to +0.
     if (y == -0.5) return 1.0 / sqrt(x + 0.0);
   }
+#else
+  if (y == 0) return 1;  // Returns 1.0 for exponent 0.
 #endif
   if (isnan(y) || ((x == 1 || x == -1) && isinf(y))) {
     return OS::nan_value();
   }
   return pow(x, y);
 }
 
 
 ExternalReference ExternalReference::power_double_double_function(
     Isolate* isolate) {
@@ skipping 128 matching lines @@
     assembler_->RecordRelocInfo(RelocInfo::POSITION, state_.current_position);
     state_.written_position = state_.current_position;
     written = true;
   }
 
   // Return whether something was written.
   return written;
 }
 
 } }  // namespace v8::internal