Cannot define time.Duration global variables

Currently you cannot define a global variable like
```go
var Timeout = time.Second * 2
// or
const Timeoutconst = time.Second * 2
```
Because we get a compiler error:
```
 initializer element is not constant
   12 | time_Duration net_TCPConnectTimeout = time_Second * 5;
      |                                       ^~~~~~~~~~~
```