<AWT Dev> RFR: 8252999: replace all String.equals("") usages with String.isEmpty()

[thatsIch]

On Sun, 6 Sep 2020 13:57:19 GMT, Dmitriy Dumanskiy <github.com+1536494+doom369 at openjdk.org> wrote:

> **isEmpty** is faster + has less byte code + easier to read. Benchmarks could be found
>   [here](https://medium.com/javarevisited/micro-optimizations-in-java-string-equals-22be19fd8416).

@doom369 jcheck requires an associated issue

-------------

PR: https://git.openjdk.java.net/jdk/pull/29