RFR: 8340273: Remove CounterHalfLifeTime

[David Holmes]

On Tue, 17 Sep 2024 09:04:03 GMT, Daniel Lundén <dlunden at openjdk.org> wrote:

> The CounterHalfLifeTime flag is no longer used and should be removed.
> 
> ### Changeset
> 
> Remove CounterHalfLifeTime.
> 
> ### Testing
> 
> N/A

LGTM2

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Marked as reviewed by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/21034#pullrequestreview-2309076017