Eager finalization and smart pointers

[Mason]

@mkitti

I think there is a problem.

julia> Base.@assume_effects :nothrow :notaskstate inlinable_libc_free(r) = Libc.free(r[])
inlinable_libc_free (generic function with 1 method)

julia> function foo()
           r = Ref(Ptr{Int}(Libc.malloc(sizeof(Int))))
           finalizer(inlinable_libc_free, r)
           unsafe_store!(r[], 5)
           unsafe_load(r[])
       end
foo (generic function with 1 method)

I think the problem here is that unsafe_load(r[]) gets linearized to

_1 = r[]
# <------- No more references to r, so the finalizer gets inserted here!
unsafe_load(_1)
# <------- You actually want the finalizer to be inserted here