RFR: 8272735: Add missing SubL node transformations

[Ahmed Muhsin]

On Wed, 9 Mar 2022 14:51:43 GMT, Tobias Hartmann <thartmann at openjdk.org> wrote:

>> This change adds/enables missing subnode transformations for operations of type `long`.
>> A few comments in the test file `SubINodeIdealizationTests.java` were modified to add clarity and to fix a typo.
>> Hotspot:tier1 tests were run, this change does not introduce any new failures.
>
> Did you sync up with @JohnTortugo on this (because the JBS issue is assigned to him)? It's not clear to me if you addressed all the issues that Cesar listed in the description.

Hey @TobiHartmann. Yep, @JohnTortugo and I reviewed this change together offline. The `AddINode` and `AddLNode` items that Cesar listed in his JBS issue were taken care of in [JDK-8278471: Remove unreached rules in AddNode::IdealIL](https://bugs.openjdk.java.net/browse/JDK-8278471#). This PR resolves the items that are left.

-------------

PR: https://git.openjdk.java.net/jdk/pull/7669