hg: jdk7/build/langtools: 6631003: Add hg tip changeset to build image

[kelly . ohair]

Changeset: c2e7291e98e7
Author:    ohair
Date:      2011-04-26 16:22 -0700
URL:       http://hg.openjdk.java.net/jdk7/build/langtools/rev/c2e7291e98e7

6631003: Add hg tip changeset to build image
Reviewed-by: mduigou

! .hgignore