RFR: 8257418: C2: Rename barrier data member in MemNode and LoadStoreNode

[Per Liden]

On Mon, 30 Nov 2020 13:15:23 GMT, Vladimir Ivanov <vlivanov at openjdk.org> wrote:

>> Please review this trivial cleanup, which renames the "barrier data" member in `MemNode` and `LoadStoreNode` from `_barrier` to `_barrier_data`, to better match the names of the setters and getters (`barrier_data()` and `set_barrier_data()`).
>
> Looks good and trivial

Thanks for reviewing, @iwanowww!

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PR: https://git.openjdk.java.net/jdk/pull/1516