LibJS: Convert to_bigint_uint64() to ThrowCompletionOr

Author: https://github.com/IdanHo
Commit: 51c33b3b35
Pull-request: https://github.com/SerenityOS/serenity/pull/10504
Reviewed-by: https://github.com/linusg

Userland/Libraries/LibJS/Runtime/Value.cpp

@@ -553,9 +553,9 @@ ThrowCompletionOr<i64> Value::to_bigint_int64(GlobalObject& global_object) const
 }
 
 // 7.1.16 ToBigUint64 ( argument ), https://tc39.es/ecma262/multipage/abstract-operations.html#sec-tobiguint64
-u64 Value::to_bigint_uint64(GlobalObject& global_object) const
+ThrowCompletionOr<u64> Value::to_bigint_uint64(GlobalObject& global_object) const
 {
-    auto* bigint = TRY_OR_DISCARD(to_bigint(global_object));
+    auto* bigint = TRY(to_bigint(global_object));
     return bigint->big_integer().to_u64();
 }