Rollup merge of #83643 - JohnTitor:is-freeze-no-longer-uses-span, r=RalfJung
Rollup merge of #83643 - JohnTitor:is-freeze-no-longer-uses-span, r=RalfJung

Remove a FIXME resolved by #73578

r? ``@RalfJung``

graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust