hg: jdk9/dev/langtools: 8031567: Better model for storing source revision information

[magnus.ihse.bursie at oracle.com]

Changeset: 3dc39a1ffca4
Author:    ihse
Date:      2016-11-28 09:20 +0100
URL:       http://hg.openjdk.java.net/jdk9/dev/langtools/rev/3dc39a1ffca4

8031567: Better model for storing source revision information
Reviewed-by: erikj

! .hgignore