the BPF maps and pointers were previously
implicitly dereferenced whenever an operation
on them required a value and not a pointer.
the upside is that accessing map element data
didn’t require an explicit operation, the downside
is that it wasn’t possible to get the value
explicitly.

this makes it possible to dereference any pointer
and materialize the value in the register as long
as it’s shorter than register width using `ptr[0]`
element access operator.