RFR: 8287726: Fix JVMTI tests with "requires vm.continuations" after JDK-8287496

[Alan Bateman]

On Thu, 2 Jun 2022 09:54:31 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> [JDK-8287496](https://bugs.openjdk.java.net/browse/JDK-8287496) brought the alternative Loom implementation that can be used by ports as the fallback. That fallback does not support JVMTI entirely, so lots of tests fail. Some JVMTI is still supported, so cutting off at `@requires vm.jvmti` seems too broad. They should be predicated with `@requires vm.continuations` to be skipped when fallback is used.
> 
> This also allows reverting relevant x86_32 problemlist exclusions.
> 
> Additional testing:
>  - [x] Linux x86_32 fastdebug, `serviceability/jvmti` works, many tests skipped
>  - [x] Linux x86_64 fastdebug, `serviceability/jvmti` still works, with all current tests executing

Marked as reviewed by alanb (Reviewer).

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PR: https://git.openjdk.java.net/jdk/pull/8990