use array.is instead of instanceof

src/mol-base/collections/integer/impl/sorted-array.ts

@@ -15,7 +15,7 @@ export function ofSortedArray(xs: Nums) {
     return xs;
 }
 export function ofUnsortedArray(xs: Nums) { sortArray(xs); return xs; }
-export function is(xs: any): xs is Nums { return xs && (xs instanceof Array || !!xs.buffer); }
+export function is(xs: any): xs is Nums { return xs && (Array.isArray(xs) || !!xs.buffer); }
 
 export function start(xs: Nums) { return xs[0]; }
 export function end(xs: Nums) { return xs[xs.length - 1] + 1;  }

src/mol-data/atom-set/base.ts

@@ -176,7 +176,7 @@ export function values(set: AtomSetImpl): Iterator<Atom> {
 }
 
 function isArrayLike(x: any): x is ArrayLike<Atom> {
-    return x && (typeof x.length === 'number' && (x instanceof Array || !!x.buffer));
+    return x && (typeof x.length === 'number' && (Array.isArray(x) || !!x.buffer));
 }
 
 function ofObject(data: { [id: number]: OrderedSet }) {