This mostly is just a simple copy of openjdk12 with changed links.  openjdk13 is also included as it must be used to bootstrap openjdk14.

openjdk14 uses "help" as a rather poor choice of autoconf test for the availability of a shell builtin and this isn't available in bash-minimal, so a small patch is needed to make configure complete.  I've contacted the openjdk developers with a suggested change but so far have had no response after a couple of business days.