BigInt: fix input values to be type BigInt

test/built-ins/TypedArrayConstructors/from/BigInt/custom-ctor-returns-smaller-instance-throws.js

@@ -22,7 +22,7 @@ includes: [testBigIntTypedArray.js]
 features: [BigInt, Symbol.iterator, TypedArray]
 ---*/
 
-var sourceItor = [1, 2];
+var sourceItor = [1n, 2n];
 var sourceObj = {
   length: 2
 };

test/built-ins/TypedArrayConstructors/from/BigInt/mapfn-abrupt-completion.js

@@ -18,7 +18,7 @@ features: [BigInt, TypedArray]
 ---*/
 
 var source = {
-  "0": 42,
+  "0": 42n,
   length: 2
 };
 var mapfn = function() {