git: openjdk/jdk: 8300864: Declare some fields in java.io as final

[Per Minborg]

Changeset: 079255e3
Author:    Per Minborg <pminborg at openjdk.org>
Date:      2023-01-23 17:40:13 +0000
URL:       https://git.openjdk.org/jdk/commit/079255e312a60584d748babcd320eacec99c5a02

8300864: Declare some fields in java.io as final

Reviewed-by: rriggs, lancea

! src/java.base/share/classes/java/io/BufferedInputStream.java
! src/java.base/share/classes/java/io/BufferedReader.java
! src/java.base/share/classes/java/io/ExpiringCache.java
! src/java.base/share/classes/java/io/File.java
! src/java.base/share/classes/java/io/FileOutputStream.java
! src/java.base/share/classes/java/io/ObjectStreamClass.java
! src/java.base/share/classes/java/io/StringReader.java
! src/java.base/share/classes/java/io/StringWriter.java