hg: jdk/sandbox: Now new fixpath seems to work, on cygwin.

[magnus.ihse.bursie at oracle.com]

Changeset: c7be52410aaa
Author:    ihse
Date:      2020-07-04 16:34 +0200
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/c7be52410aaa

Now new fixpath seems to work, on cygwin.

! make/autoconf/basic_windows.m4
! make/scripts/fixpath.sh