[jdk17u] RFR: 8277385: Zero: Enable CompactStrings support

[Aleksey Shipilev]

On Mon, 22 Nov 2021 11:02:18 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> Clean backport to improve Zero performance.
> 
> Additional testing:
>  - [x] Linux x86_64 fastdebug `make bootcycle-images`
>  - [x]  Linux x86_32 fastdebug `make bootcycle-images`

Transplanted to https://github.com/openjdk/jdk17u-dev/pull/5.

-------------

PR: https://git.openjdk.java.net/jdk17u/pull/296