YJIT: Move ocb parameters into JITState

Many functions take an outlined code block but do nothing more than
passing it along; only a couple of functions actually make use of it.
So, in most cases the `ocb` parameter is just boilerplate.

Most functions that take `ocb` already also take a `JITState` and this
commit moves `ocb` into `JITState` to remove the visual noise of the
`ocb` parameter.

Author: XrXr