fix for single threaded configurations

[Andrew Haley]

Andreas Tobler writes:
 > 
 > 2006-08-01  Andreas Tobler  <a.tobler@schweiz.ch>
 > 
 > 	* gnu/classpath/natSystemProperties.cc: Add additional check for
 > 	getpwuid_r on _POSIX_PTHREAD_SEMANTICS.
 > 	(SystemProperties::insertSystemProperties): Likewise.
 > 	* java/io/natFilePosix.cc (File::performList): Add
 > 	additional check for readdir_r on _POSIX_PTHREAD_SEMANTICS.
 > 	* java/util/natVMTimeZone.cc (VMTimeZone::getSystemTimeZoneId): Add
 > 	additional check for localtime_r on _POSIX_PTHREAD_SEMANTICS.

OK.

Andrew.