WeakHeap => WeakSet
        HandleHeap => HandleSet

Reviewed by Sam Weinig.

These sets do have internal allocators, but it's confusing to call them
heaps because they're sub-objects of an object called "heap".

* heap/HandleHeap.cpp: Removed.
* heap/HandleHeap.h: Removed.
* heap/HandleSet.cpp: Copied from JavaScriptCore/heap/HandleHeap.cpp.
* heap/WeakHeap.cpp: Removed.
* heap/WeakHeap.h: Removed.
* heap/WeakSet.cpp: Copied from JavaScriptCore/heap/WeakHeap.cpp.
* heap/WeakSet.h: Copied from JavaScriptCore/heap/WeakHeap.h.

Plus global rename using grep.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@113508 268f45cc-cd09-0410-ab3c-d52691b4dbfc