- replace hash functions  with better ones

        * JavaScriptCore.pbproj/project.pbxproj: Add new file to build.
        * kjs/interpreter_map.cpp:
        (KJS::InterpreterMap::computeHash): Use shared pointer hash.
        * kjs/pointer_hash.h: Added.
        (KJS::pointerHash): Pointer hash based on 32-bit mix and 64-bit mix hashes.
        * kjs/protected_values.cpp:
        (KJS::ProtectedValues::computeHash): Use shared pointer hash.
        * kjs/ustring.cpp:
        (KJS::UString::Rep::computeHash): Use SuperFastHash algorithm.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@9501 268f45cc-cd09-0410-ab3c-d52691b4dbfc