hg: jdk/submit12: 8215635: Pandoc check in Docs.gmk does not work on Windows

[erik.joelsson at oracle.com]

Changeset: f48737b2f428
Author:    erikj
Date:      2018-12-20 05:27 -0800
URL:       http://hg.openjdk.java.net/jdk/submit12/rev/f48737b2f428

8215635: Pandoc check in Docs.gmk does not work on Windows
Reviewed-by: tbell, ihse

! make/Docs.gmk
! make/autoconf/basics.m4
! make/autoconf/spec.gmk.in
! make/launcher/LauncherCommon.gmk