Update java/io/ObjectStreamClass.java in 4.0 branch from Classpath

[Tom Tromey]

>>>>> "Andrew" == Andrew Haley <aph@redhat.com> writes:

Andrew> This merges java/io/ObjectStreamClass.java.  The version in libgcj is
Andrew> no use for anything.

Are there any differences now between the Classpath copy and the
libgcj copy?  If not, then once the trunk is un-slushy (or earlier if
this is important), we ought to remove the libgcj-specific copy there.

Tom