RFR: 8354383: C2: enable sinking of Type nodes out of loop

[Tobias Hartmann]

On Thu, 22 May 2025 15:53:18 GMT, Roland Westrelin <roland at openjdk.org> wrote:

> `PhaseIdealLoop::try_sink_out_of_loop()` excludes `Type` nodes because
> we ran into some issues where a `Type` node is sunk and then becomes
> `top` but the control path of its uses doesn't become unreachable.
> 
> 8349479 should have fixed that so that exception no longer makes
> sense.

That looks good to me but given that we had quite a few bugs in that area in the past, I would suggest to only integrate into JDK 26 after the fork on June 05, 2025.

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Marked as reviewed by thartmann (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/25396#pullrequestreview-2863393272