git: openjdk/jdk: 8217496: Matcher.group() can return null after usePattern

[Ian Graves]

Changeset: ac3ab5b0
Author:    Ian Graves <igraves at openjdk.org>
Date:      2023-03-07 17:20:04 +0000
URL:       https://git.openjdk.org/jdk/commit/ac3ab5b00754a6d96dcb107edb7b82ba582f15b9

8217496: Matcher.group() can return null after usePattern

Reviewed-by: smarks

! src/java.base/share/classes/java/util/regex/Matcher.java