> From a build perspective this partially reverts https://bugs.openjdk.java.net/browse/JDK-8249821 except that it keeps
> the harfbuzz sources separate and still supports building and running against a system harfbuzz which is only of interest or relevance on Linux.
> I ended up having to go this way because its is the least unsatisfactory solution.
> I did not want us to build a devkit to link against a system linux only to find we couldn't use it at runtime
> because too many systems have to old a version of harfbuzz.
> This solves the Manjaro Linux problem and I've manually verified building against a system hardbuxz on Ubuntu 20.10
> There are couple of incidental fixes in here too
> - "libharfbuzz" should not have been in the EXTRA_HEADERS var when building against a system version
> - harfbuzz/hb-ucdn is gone and should not be listed as a header directory needed to build the bundled copy
> - I expect it also resolves https://bugs.openjdk.java.net/browse/JDK-8262502