Use have/need data in ArcanistPhutilLibraryLinter

Summary: Ref T5640. In D9864, the data this linter pulls out of the map was changed, breaking "use of undeclared function" warnings.

Test Plan:
```
>>> Lint for src/future/FutureProxy.php:

   Error  (PHL1) Unknown Symbol
    Use of unknown function 'qqqqqq'. Common causes are:

      - Your libphutil/ is out of date.
        This is the most common cause.
        Update this copy of libphutil: /INSECURE/devtools/libphutil

      - Some other library is out of date.
        Update the library this symbol appears in.

      - This symbol is misspelled.
        Spell the symbol name correctly.
        Symbol name spelling is case-sensitive.

      - This symbol was added recently.
        Run `arc liberate` on the library it was added to.

      - This symbol is external. Use `@phutil-external-symbol`.
        Use `grep` to find usage examples of this directive.

    *** ALTHOUGH USUALLY EASY TO FIX, THIS IS A SERIOUS ERROR.
    *** THIS ERROR IS YOUR FAULT. YOU MUST RESOLVE IT.

              15       $this->setProxiedFuture($proxied);
              16     }
              17
    >>>       18     qqqqqq();
              19   }
              20
              21   public function setProxiedFuture(Future $proxied) {
```

Reviewers: joshuaspence

Reviewed By: joshuaspence

Subscribers: epriestley

Maniphest Tasks: T5640

Differential Revision: https://secure.phabricator.com/D9954