hg: jdk/sandbox: Clean up help stuff, add descriptions. Sort legacy and create aliases.

[magnus.ihse.bursie at oracle.com]

Changeset: 903ca5e00514
Author:    ihse
Date:      2020-02-21 14:09 +0100
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/903ca5e00514

Clean up help stuff, add descriptions. Sort legacy and create aliases.

! make/autoconf/basics.m4
! make/autoconf/help.m4
! make/autoconf/jdk-features.m4
! make/autoconf/jvm-features.m4