hg: jdk/sandbox: 8229022: BufferedReader performance can be improved by using StringBuilder

[chris.hegarty at oracle.com]

Changeset: ed0058d06107
Author:    bpb
Date:      2019-10-02 07:50 -0700
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/ed0058d06107

8229022: BufferedReader performance can be improved by using StringBuilder
Reviewed-by: igerasim, vtewari, dfuchs

! src/java.base/share/classes/java/io/BufferedReader.java