RFR: 8328107: Shenandoah/C2: TestVerifyLoopOptimizations test failure

[Aleksey Shipilev]

On Thu, 16 May 2024 07:37:46 GMT, Roland Westrelin <roland at openjdk.org> wrote:

> The failure occurs because a load barrier is expanded on the backedge
> of the counted loop. That breaks the expected counted loop shape. The
> fix I propose is to replace the `CountedLoop` with a `Loop` node when
> that happens. We're basically done with optimizations related to
> counted loop at this point so this shouldn't make a difference.

This looks reasonable, thanks. Passes all the tests I throw at it.

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Marked as reviewed by shade (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/19259#pullrequestreview-2093136958