hg: build-infra/jdk8: * Add support for checking out code in cygwin /home directory.

[magnus.ihse.bursie at oracle.com]

Changeset: b3b4d8e5b0d5
Author:    ihse
Date:      2012-09-20 15:12 +0200
URL:       http://hg.openjdk.java.net/build-infra/jdk8/rev/b3b4d8e5b0d5

* Add support for checking out code in cygwin /home directory.
* Add sanity check that cygdrive prefix is /cygdrive.

! common/autoconf/basics.m4
! common/autoconf/generated-configure.sh