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)

Instead of allocating at CTFE maybe just loop through it using slicing and compare operator?

Roughly like this:
```
string s = fun;
s.skipWs.skip(paramName1).skipWs.skip(paramName2).skipWs;
return s.length == 0;
```

where skip and skipWs skip over fixed string and spaces respectively.