This updates OpenJDK 8 to a newer version and brings a bunch of
changes.
Newly, it is bootstrapped with openjdk7-bootstrap, so it does not
need to download binaries. It can also cross-compile and is patched
for musl and other platforms.
We're newly using the aarch64 port repo in order to get aarch64
JIT. For non-aarch64 platforms, the codebase is the same.
The symlink for /usr/lib/jvm/openjdk is also now gone and we're
using a unified java-VERSION-VENDOR naming.
Also general template cleanup.
[ci skip]
6783ab9f47