[jdk19] RFR: 8289302: Restore CriticalJNINatives

[Kirill Prazdnikov]

On Wed, 29 Jun 2022 12:10:35 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

> This change restores the code in the JVM that implemented the internal JavaCritical or CriticalJNINatives functionality.  Customers are using this feature and there's no replacement yet for it.
> This change is a backout and merge of jDK-8258192: Obsolete the CriticalJNINatives flag.
> This change also adds the deprecation message that was missed, which I checked is okay with the customer.
> 
> Tested with tiers1-4.

I can confirm very significant performance drop. We have been using JavaCritical for OpenGL calls, for FreeType & HarfBuzz calls,
for libPNG interop, for TurboJPEG interop. Basically for everything and it makes a very significant performance gain

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PR: https://git.openjdk.org/jdk19/pull/90