This adds explicit lifetimes to any function which looks at a NIR
object, fishes a pointer out of it, and returns a reference. The theory
of operation for these NIR wrappers is that everything holds an implicit
shared reference to the whole shader and so this is safe to do as long
as no one ever has a mut reference to anything. However, since these
methods are turning pointers into references, it's a lot more obvious
what's going on if we have explicit lifetimes.
Reviewed-by: Christian Gmeiner <cgmeiner@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30443>
