[master] RFR: 8308900: [Lilliput] Cherry-pick C2 prototype header improvements

Fri May 26 07:52:48 UTC 2023

On Thu, 25 May 2023 19:21:47 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> This cherry-picks the commit from the upstream review: https://github.com/rkennke/jdk/commit/3a18945ce900e229331b1412002da4a6965e0764.
> 
> It also fixes the affected code with more `UseCompactObjectHeaders` guards, and partially reverts it to upstream state.
> 
> Additional testing:
>  - [x] Linux x86_64 fastdebug `tier1`
>  - [x] Linux x86_64 fastdebug `tier1` + `+UseCompactObjectHeaders`

Thanks!

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PR Comment: https://git.openjdk.org/lilliput/pull/95#issuecomment-1563958327