RFR: JDK-8189094: Change required boot jdk to JDK 9

[Jonathan Gibbons]

On 10/16/17 11:53 AM, Martin Buchholz wrote:
> What's the canonical way to list all upgradeable modules?
> There's a list in JEP 261, but naturally we can't consider it authoritative.
>
> I was surprised that even java --describe-module doesn't tell me whether a
> module is upgradeable.
>
> I was surprised to see JEP 261 say that java.compiler is upgradeable, but
> not jdk.compiler.
> Perhaps thinking of the bootstrap use case?
java.compiler is upgradeable to allow alternate implementations, such as
in the bootstrap case, and in IDEs that want to run on older JDKs and still
use compile-time reflection using javax.lang.model API.

jdk.compiler is not upgradeable, because it is tied into other modules, and
we don't want to claim to support general mix-n-match of these modules.

-- Jon