Implement the type version of Array.indexOf

IndexOf<T, U> takes an Array of T, any U and returns the index of the first U in Array of T.

For example:

type Res1 = IndexOf<[1, 2, 3], 2>; // expected to be 1
type Res2 = IndexOf<[2,6, 3,8,4,1,7, 3,9], 3>; // expected to be 2
type Res3 = IndexOf<[0, 0, 0], 2>; // expected to be -1