Create interface file does not work with React.memo

[cknitt]

@cristianoc Thanks for your great work on getting the "Create interface file" feature to work for React components, too! 👍

I just tested it with the VSIX from the lastest master build and found that components memoized with React.memo do not work correctly yet.

For example,

@react.component
let make = (~someValue as _: bool) => React.null

let make = React.memo(make)

results in

let make: React.component<{"someValue": bool}>

instead of

@react.component
let make: (~someValue: bool) => React.element

[cristianoc]

Thanks!
Done in master.