=== tests/cases/compiler/duplicateOverloadInTypeAugmentation1.ts ===
interface Array<T> {
>Array : T[], Symbol(Array, Decl(lib.d.ts, 1000, 23), Decl(lib.d.ts, 1171, 11), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 0))
>T : T, Symbol(T, Decl(lib.d.ts, 1007, 16), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 16))

    reduce(callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T,
>reduce : { (callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue?: T): T; <U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; (callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue?: T): T; <U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; }, Symbol(reduce, Decl(lib.d.ts, 1129, 93), Decl(lib.d.ts, 1136, 120), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 20), Decl(duplicateOverloadInTypeAugmentation1.ts, 2, 29))
>callbackfn : (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, Symbol(callbackfn, Decl(duplicateOverloadInTypeAugmentation1.ts, 1, 11))
>previousValue : T, Symbol(previousValue, Decl(duplicateOverloadInTypeAugmentation1.ts, 1, 24))
>T : T, Symbol(T, Decl(lib.d.ts, 1007, 16), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 16))
>currentValue : T, Symbol(currentValue, Decl(duplicateOverloadInTypeAugmentation1.ts, 1, 41))
>T : T, Symbol(T, Decl(lib.d.ts, 1007, 16), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 16))
>currentIndex : number, Symbol(currentIndex, Decl(duplicateOverloadInTypeAugmentation1.ts, 1, 58))
>array : T[], Symbol(array, Decl(duplicateOverloadInTypeAugmentation1.ts, 1, 80))
>T : T, Symbol(T, Decl(lib.d.ts, 1007, 16), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 16))
>T : T, Symbol(T, Decl(lib.d.ts, 1007, 16), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 16))

        initialValue?: T): T;
>initialValue : T, Symbol(initialValue, Decl(duplicateOverloadInTypeAugmentation1.ts, 1, 98))
>T : T, Symbol(T, Decl(lib.d.ts, 1007, 16), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 16))
>T : T, Symbol(T, Decl(lib.d.ts, 1007, 16), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 16))

    reduce<U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U,
>reduce : { (callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue?: T): T; <U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; (callbackfn: (previousValue: T, currentValue: T, currentIndex: number, array: T[]) => T, initialValue?: T): T; <U>(callbackfn: (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, initialValue: U): U; }, Symbol(reduce, Decl(lib.d.ts, 1129, 93), Decl(lib.d.ts, 1136, 120), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 20), Decl(duplicateOverloadInTypeAugmentation1.ts, 2, 29))
>U : U, Symbol(U, Decl(duplicateOverloadInTypeAugmentation1.ts, 3, 11))
>callbackfn : (previousValue: U, currentValue: T, currentIndex: number, array: T[]) => U, Symbol(callbackfn, Decl(duplicateOverloadInTypeAugmentation1.ts, 3, 14))
>previousValue : U, Symbol(previousValue, Decl(duplicateOverloadInTypeAugmentation1.ts, 3, 27))
>U : U, Symbol(U, Decl(duplicateOverloadInTypeAugmentation1.ts, 3, 11))
>currentValue : T, Symbol(currentValue, Decl(duplicateOverloadInTypeAugmentation1.ts, 3, 44))
>T : T, Symbol(T, Decl(lib.d.ts, 1007, 16), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 16))
>currentIndex : number, Symbol(currentIndex, Decl(duplicateOverloadInTypeAugmentation1.ts, 3, 61))
>array : T[], Symbol(array, Decl(duplicateOverloadInTypeAugmentation1.ts, 3, 83))
>T : T, Symbol(T, Decl(lib.d.ts, 1007, 16), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 16))
>U : U, Symbol(U, Decl(duplicateOverloadInTypeAugmentation1.ts, 3, 11))

        initialValue: U): U;
>initialValue : U, Symbol(initialValue, Decl(duplicateOverloadInTypeAugmentation1.ts, 3, 101))
>U : U, Symbol(U, Decl(duplicateOverloadInTypeAugmentation1.ts, 3, 11))
>U : U, Symbol(U, Decl(duplicateOverloadInTypeAugmentation1.ts, 3, 11))
}
var a: Array<string>;
>a : string[], Symbol(a, Decl(duplicateOverloadInTypeAugmentation1.ts, 6, 3))
>Array : T[], Symbol(Array, Decl(lib.d.ts, 1000, 23), Decl(lib.d.ts, 1171, 11), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 0))

var r5 = a.reduce((x, y) => x + y);
>r5 : string, Symbol(r5, Decl(duplicateOverloadInTypeAugmentation1.ts, 7, 3))
>a.reduce((x, y) => x + y) : string
>a.reduce : { (callbackfn: (previousValue: string, currentValue: string, currentIndex: number, array: string[]) => string, initialValue?: string): string; <U>(callbackfn: (previousValue: U, currentValue: string, currentIndex: number, array: string[]) => U, initialValue: U): U; (callbackfn: (previousValue: string, currentValue: string, currentIndex: number, array: string[]) => string, initialValue?: string): string; <U>(callbackfn: (previousValue: U, currentValue: string, currentIndex: number, array: string[]) => U, initialValue: U): U; }, Symbol(Array.reduce, Decl(lib.d.ts, 1129, 93), Decl(lib.d.ts, 1136, 120), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 20), Decl(duplicateOverloadInTypeAugmentation1.ts, 2, 29))
>a : string[], Symbol(a, Decl(duplicateOverloadInTypeAugmentation1.ts, 6, 3))
>reduce : { (callbackfn: (previousValue: string, currentValue: string, currentIndex: number, array: string[]) => string, initialValue?: string): string; <U>(callbackfn: (previousValue: U, currentValue: string, currentIndex: number, array: string[]) => U, initialValue: U): U; (callbackfn: (previousValue: string, currentValue: string, currentIndex: number, array: string[]) => string, initialValue?: string): string; <U>(callbackfn: (previousValue: U, currentValue: string, currentIndex: number, array: string[]) => U, initialValue: U): U; }, Symbol(Array.reduce, Decl(lib.d.ts, 1129, 93), Decl(lib.d.ts, 1136, 120), Decl(duplicateOverloadInTypeAugmentation1.ts, 0, 20), Decl(duplicateOverloadInTypeAugmentation1.ts, 2, 29))
>(x, y) => x + y : (x: string, y: string) => string
>x : string, Symbol(x, Decl(duplicateOverloadInTypeAugmentation1.ts, 7, 19))
>y : string, Symbol(y, Decl(duplicateOverloadInTypeAugmentation1.ts, 7, 21))
>x + y : string
>x : string, Symbol(x, Decl(duplicateOverloadInTypeAugmentation1.ts, 7, 19))
>y : string, Symbol(y, Decl(duplicateOverloadInTypeAugmentation1.ts, 7, 21))