If this gets wide enough use, they could add an optimization for code like this:

    n = 1000
    a = {}
    for i in range(n):
        a[i] = str(i)
    a = frozendict(a)  # O(n) operation can be turned to O(1)

It is relatively easy for the JIT to detect the `frozendict` constructor, the `dict` input, and the single reference immediately overwritten. Not sure if this would ever be worth it.