"typeof" operator should remove wideningness

[RyanCavanaugh]

Source https://stackoverflow.com/questions/44421946/does-typescript-2-3-3-loose-type-information-on-array-spread

This code:

const A = "A", B = "B";
type T_A = typeof A;
type T_B = typeof B;
type M = T_A | T_B;
const m: Array<M> = ["A"];
const n = [...m]; // n: string[]

behaves differently from this code, which is quite surprising:

const A = "A", B = "B";
type T_A = "A"; // was: typeof A
type T_B = "B"; // was: typeof B
type M = T_A | T_B;
const m: Array<M> = ["A"];
const n = [...m]; // n: M[], was string[]

Once someone is using typeof, it seems very unlikely they want a widening type and we should revert to a non-widening form of the type.

[RyanCavanaugh]

Nah