On my Linux Mint 19.1:
```bash
$ umask
0022
```

After the first run of `bitcoin-qt -sysperm=false` the `0700` permissions are expected for both the datadir (`~/.bitcoin`) and the walletdir (`~/.bitcoin/wallets`).

Actually, the directories are created with such access permissions:
```bash
$ stat ~/.bitcoin | grep Uid
Access: (0755/drwxr-xr-x)  Uid: ( 1000/ hebasto)   Gid: ( 1000/ hebasto)
$ stat ~/.bitcoin/wallets | grep Uid
Access: (0755/drwxr-xr-x)  Uid: ( 1000/ hebasto)   Gid: ( 1000/ hebasto)
```

Refs:
- #4286
- #13371
- #13389

NOTE: reading through the initial PR #4286 makes me think it was controversial. Is it a better and simpler way to just get rid of `-sysperm` option? I believe a user who needs this option can easily run `chown` command.
{
    return std::thread::hardware_concurrency();
}
int64_t GetStartupTime()
{
    return nStartupTime;
}
fs::path AbsPathForConfigVal(const fs::path& path, bool net_specific)
{
    if (path.is_absolute()) {
        return path;
    }
    return fsbridge::AbsPathJoin(net_specific ? gArgs.GetDataDirNet() : gArgs.GetDataDirBase(), path);
}
void ScheduleBatchPriority()
{
#ifdef SCHED_BATCH
    const static sched_param param{};
    const int rc = pthread_setschedparam(pthread_self(), SCHED_BATCH, &param);
    if (rc != 0) {
        LogPrintf("Failed to pthread_setschedparam: %s\n", SysErrorString(rc));
    }
#endif
}
namespace util {
#ifdef WIN32
WinCmdLineArgs::WinCmdLineArgs()