rdar://127199021, fix compatibility with apps that accidentally do [[[aSwiftArray class] new] mutableCopy] to work (#73728)

test/stdlib/ArrayBridge.swift.gyb

@@ -422,6 +422,11 @@ tests.test("testThunks") {
   testBridgeableValue(Thunks())
 }
 
+tests.test("testHKTFilter") {
+  let base = ["hello", "world"]
+  let result = testHKTFilter(base) as! NSArray as! [String]
+  expectEqual(result, ["hello"])
+}
 
 tests.test("testRoundTrip") {
   class Test : NSObject {