Access to RFC: Spl needs extensive improvements.

Hello, I would like to improve the Spl. Some of the problems I can fix without any approval, such as updating the documentation to update the exceptions thrown in function. However, while gathering that information I have discovered that the types of exceptions thrown inside the SPL are inconsistent. For example, *SplStack throws an OutOfRangeException* when it encounters an index that doesn't exist. encounters an index that doesn't exist. I don't agree with this choice, but that's only part of the issue. *SplFixedArray throws a generic RuntimeException* when it encounters an index that doesn't exist. I have a patch ready to fix this for SplFixedArray, but I discovered it wasn't an isolated incident. *This is inconsistent. *They should throw the same exception. Unfortunately, it breaks backwards compatibility to fix because OutOfRangeException is a LogicException. Personally, LogicException seems like a poor choice as accessing an index in other languages is always a runtime exceptions. I think OutOfBoundsException is the most appropriate. This is only the surface of the problem. I would like to propose all of the changes I think should take place. Starting an RFC seems like the best way to get others to support this change. Thank you, Levi Morrison