dip: __HERE__ special token

[monkyyy]

```
int ignored;
int referenced;
void main(){
     alias foo=referenced;
     struct bar{}
     alias faz=sometemplate!int;
     alias firstcopy=__HERE__;//foo,bar,faz
     int baz;
     alias secondcopy=__HERE__;//foo,bar,faz,firstcopy,baz
}
```

https://github.com/crazymonkyyy/DIPs/blob/master/DIPs/1NNN-MKY.md

A special token for convenience while meta programming