hg: jdk/jdk: 8215401: Add isEmpty default method to CharSequence

[claes.redestad at oracle.com]

Changeset: 275c91757a7f
Author:    redestad
Date:      2020-05-22 11:20 +0200
URL:       https://hg.openjdk.java.net/jdk/jdk/rev/275c91757a7f

8215401: Add isEmpty default method to CharSequence
Reviewed-by: jlaskey, rriggs, jjg, alanb, smarks, darcy

! src/java.base/share/classes/java/lang/CharSequence.java
! src/java.base/share/classes/java/lang/String.java
! src/java.base/share/classes/java/nio/X-Buffer.java.template
+ test/jdk/java/lang/CharSequence/Emptiness.java