Creating too many types for DOM & D3

Commit 06fe1ed53721862b56c61ebb89b1daee2bc10710 introduced a regression in the number of types created when compiling a snippet of `@types\d3`. Specifically, it appears to be elaborating types for an error message that ends up getting dropped. Repro: ```json { "compileOnSave": false, "compilerOptions": { "alwaysStrict": true, "noImplicitAny": true, "noEmit": true, "lib": [ "es5", "dom" ], "noResolve": true, "types": [], "skipLibCheck": true }, "files": [ "test.ts", } ``` test.ts ```ts declare function select<GElement extends BaseType, OldDatum>(selector: string): Selection2<GElement, OldDatum, HTMLElement, any>; type BaseType = Element | Document | Window | null | number; type ValueFn<T extends BaseType, Datum, Result> = (this: T, datum: Datum, index: number, groups: T[] | ArrayLike<T>) => Result; interface Selection2<GElement extends BaseType, Datum, PElement extends BaseType, PDatum> { select<DescElement extends BaseType>(selector: ValueFn<GElement, Datum, DescElement>): Selection2<DescElement, Datum, PElement, PDatum>; } ``` For an apples-to-apples comparison, use `nolib` and specify the 3.1 lib.es5.d.ts and lib.dom.d.ts for both compilations. In round numbers, there are ~150 types without the change and ~2500 types with the change.