hg: jdk9/sandbox/jdk: JDK-8054307-branch: fix bug at asb.setCharAt() and small cleanup

[xueming.shen at oracle.com]

Changeset: 59959d000448
Author:    sherman
Date:      2015-04-28 17:04 +0000
URL:       http://hg.openjdk.java.net/jdk9/sandbox/jdk/rev/59959d000448

JDK-8054307-branch: fix bug at asb.setCharAt() and small cleanup

! src/java.base/share/classes/java/lang/AbstractStringBuilder.java
! src/java.base/share/classes/java/lang/String.java
! src/java.base/share/classes/java/lang/StringUTF16.java