TypeScript/tests/baselines/reference/interfaceWithOptionalProperty.types

=== tests/cases/compiler/interfaceWithOptionalProperty.ts ===

interface I {
>I : I, Symbol(I, Decl(interfaceWithOptionalProperty.ts, 0, 0))

    x?: number;
>x : number, Symbol(x, Decl(interfaceWithOptionalProperty.ts, 1, 13))
}