Function helper

deps/v8/test/mjsunit/wasm/memory-resizable-buffer-array-concat.js:37–39

(receiver, ...params)

    //              [1, 2, 3, 4] << fixedLength

    function helper(receiver, ...params) {
      return ToNumbers(Array.prototype.concat.call(receiver, ...params));
    }

    // TypedArrays aren't concat spreadable by default.
    assertEquals([fixedLength, 5, 6, 7], helper(fixedLength, [5, 6], [7]));