Program(s) Feature Request: add unsafe unchecked invoke call

Hey guys,
What are your thoughts on exposing an `unsafe unchecked_invoke_signed` call for program instructions?

I'm currently building a [wrapper] on top of the Pinocchio SDK to provide "compile time" access safety. An unchecked variant of the program calls would be beneficial as it could reduce the overhead of releasing and relocking the runtime guard.

[wrapper]: https://github.com/redmannequin/sol-ez/blob/b5ced289ac9796c95ef341149531efa84d70aff6/src/sol-ez/src/account_info.rs#L160-L191