RFR: 8275586: Zero: Simplify interpreter initialization

[Aleksey Shipilev]

On Wed, 20 Oct 2021 07:44:36 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> The prolog in `BytecodeInterpreter` is hairy due to early initialization of interpreter statics. Previous rewrites make it mostly redundant, and we can now simplify it.
> 
> This also implicitly fixes a initialization bug. If `JvmtiExport::can_post_interpreter_events()` changes at runtime, we will call into the uninitialized version:
> 
> 
>     // Call the interpreter
>     if (JvmtiExport::can_post_interpreter_events()) {
>       BytecodeInterpreter::run<true>(istate);
>     } else {
>       BytecodeInterpreter::run<false>(istate);
>     } 
> 
> 
> Additional testing:
>  - [x] Linux x86_64 fastdebug `make bootcycle-images`

I think I need a second (R)eviewer for this.

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PR: https://git.openjdk.java.net/jdk/pull/6029