RFR: 8354477: C2 SuperWord: make use of memory edges more explicit

[Roland Westrelin]

On Sun, 13 Apr 2025 13:40:13 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

> This is a small refactoring, to make it more explicit that the "additional dependencies" are memory dependencies.
> 
> This is also preparatory work for [JDK-8324751](https://bugs.openjdk.org/browse/JDK-8324751), where we have two memory edge categories: strong and weak.
> 
> I was able to pass around `vtn_dependencies` in fewer occasions, and also renamed it to `vtn_memory_dependencies`.

Looks reasonable to me.

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Marked as reviewed by roland (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/24613#pullrequestreview-2778595641