fix binaryFun

1. Make binaryFun correct for integer comparison.
2. Remove import of half of phobos for 98% cases in phobos.

`sort`, `cmp`, `find`, `startsWith`,  `sum` and other algorithms would be compiled faster.

See also: #2701, [Issue 13253 - use more scoped imports in phobos](https://issues.dlang.org/show_bug.cgi?id=13253)

And it slowly gets to the point where we can as well parse simple expressions, just need a stack and precedence rules... :)

Serioulsly this would also benefit from pattern-matching style view of things:
```
return s.skipWs.skip(parm1Name)
    .skipAny("([").skipWs.skip(param2Name).skipWs.skipAny(")]").skipWs.length == 0;
```