[8u] RFR 8229022: BufferedReader performance can be improved by using StringBuilder

[Zhengyu Gu]

Looks good to me.

-Zhengyu

On 2/20/20 7:29 AM, Aleksey Shipilev wrote:
> Original fix:
>    https://bugs.openjdk.java.net/browse/JDK-8229022
>    https://hg.openjdk.java.net/jdk/jdk/rev/ed0058d06107
> 
> Patch does not apply cleanly to 8u, because context is different. Reapplying hunks by hand yield
> this 8u webrev:
>    https://cr.openjdk.java.net/~shade/8229022/webrev.8u.01/
> 
> Testing: tier1
>