[Array concat has wrong types](https://github.com/microsoft/TypeScript/issues/47351), so maybe we should add an `arrayConcat` function as a quick fix. See https://github.com/microsoft/TypeScript/issues/36554#issuecomment-580924501, https://github.com/microsoft/TypeScript/issues/41913, https://github.com/microsoft/TypeScript/pull/33645 for more use cases.
Array concat has wrong types, so maybe we should add an
arrayConcatfunction as a quick fix.See microsoft/TypeScript#36554 (comment), microsoft/TypeScript#41913, microsoft/TypeScript#33645 for more use cases.