hg: jdk/sandbox: 8234689: facilitate writing additional custom attributes in a class file

[chris.hegarty at oracle.com]

Changeset: 17b0f051280f
Author:    jjg
Date:      2019-12-09 12:27 -0800
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/17b0f051280f

8234689: facilitate writing additional custom attributes in a class file
Reviewed-by: jlahoda

! src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/ClassWriter.java
+ test/langtools/tools/javac/classwriter/ExtraAttributes.java