no hashable for char

Stream: new members

[Alok Singh]

i was surprised there's no instance for it, is this intentional?

[Alex J. Best]

Mathlib has it in docs#Mathlib.Tactic.Superscript.instHashableChar. I would guess that this should be in std, or elsewhere in mathlib at least (I found this with loogle). I think its intentional inasmuchas core only includes things that are really needed for Lean itself and its builtin tactics to function, or that can't be defined later