java.io fix and speedup

[Tom Tromey]

>>>>> "Mark" == Mark Wielaard <mark@klomp.org> writes:

Mark> * java/io/FileInputStream.java (finalize): Don't explicitly
Mark> finalize FileDescriptor.

This part is fine; please check it in asap.

Mark> * java/io/FileDescriptor.java (position): New private field.
Mark> * java/io/natFileDescriptorPosix.cc (write): Up position.
Mark> (setLength): Use and set position.
Mark> (seek): Set position.
Mark> (getFilePointer): Return position.
Mark> (read): Up position.

With this part, what if two processes are modifying the same file at
the same time?  I suppose even the current code has problems in that
situation.  Is the performance of setLength and seek important?

Tom