hg: jdk8u/jdk8u-dev: 8222975: Fix 'release' file to reflect actual repo checkin used to compile JDK

[gnu.andrew at redhat.com]

Changeset: 84adf64edebb
Author:    stooke
Date:      2019-04-26 17:11 +0100
URL:       http://hg.openjdk.java.net/jdk8u/jdk8u-dev/rev/84adf64edebb

8222975: Fix 'release' file to reflect actual repo checkin used to compile JDK
Summary: Use 'hg id -i' instead of 'hg tip' for obtaining the source revision
Reviewed-by: andrew

! make/common/MakeBase.gmk