Reviewed by Sam Weinig & Darin Adler.

Encapsulate, reduce duplication of table search code,
and reduce the size of the tables (remove the index,
just maintain the tables in the correct order).

Shows a 0.5% - 1% progression on sunspider.

../JavaScriptCore: 

* JavaScriptCore.exp:
* runtime/PropertyMapHashTable.h:
(JSC::isPowerOf2):
(JSC::nextPowerOf2):
    bit ops used to calculate table size.
(JSC::PropertyMapEntry::PropertyMapEntry):
(JSC::PropertyTable::ordered_iterator::operator++):
(JSC::PropertyTable::ordered_iterator::operator==):
(JSC::PropertyTable::ordered_iterator::operator!=):
(JSC::PropertyTable::ordered_iterator::operator*):
(JSC::PropertyTable::ordered_iterator::operator->):
(JSC::PropertyTable::ordered_iterator::ordered_iterator):
    implementation of the iterator types
(JSC::PropertyTable::PropertyTable):
(JSC::PropertyTable::~PropertyTable):
    constructors take an initial capacity for the table,
    a table to copy, or both.
(JSC::PropertyTable::begin):
(JSC::PropertyTable::end):
    create in-order iterators.
(JSC::PropertyTable::find):
    search the hash table
(JSC::PropertyTable::add):
    add a value to the hash table
(JSC::PropertyTable::remove):
    remove a value from the hash table
(JSC::PropertyTable::size):
(JSC::PropertyTable::isEmpty):
    accessors.
(JSC::PropertyTable::propertyStorageSize):
(JSC::PropertyTable::clearDeletedOffsets):
(JSC::PropertyTable::hasDeletedOffset):
(JSC::PropertyTable::getDeletedOffset):
(JSC::PropertyTable::addDeletedOffset):
    cache deleted (available) offsets in the property storage array.
(JSC::PropertyTable::copy):
    take a copy of the PropertyTable, potentially expanding the capacity.
(JSC::PropertyTable::sizeInMemory):
    used for DEBUG build statistics
(JSC::PropertyTable::reinsert):
(JSC::PropertyTable::rehash):
(JSC::PropertyTable::tableCapacity):
(JSC::PropertyTable::deletedEntryIndex):
(JSC::PropertyTable::skipDeletedEntries):
(JSC::PropertyTable::table):
(JSC::PropertyTable::usedCount):
(JSC::PropertyTable::dataSize):
(JSC::PropertyTable::sizeForCapacity):
(JSC::PropertyTable::canInsert):
    these methods provide internal implementation.
* runtime/Structure.cpp:
(JSC::Structure::dumpStatistics):
(JSC::Structure::~Structure):
(JSC::Structure::materializePropertyMap):
(JSC::Structure::despecifyDictionaryFunction):
(JSC::Structure::addPropertyTransition):
(JSC::Structure::flattenDictionaryStructure):
(JSC::Structure::copyPropertyTable):
(JSC::Structure::get):
(JSC::Structure::despecifyFunction):
(JSC::Structure::despecifyAllFunctions):
(JSC::Structure::put):
(JSC::Structure::remove):
(JSC::Structure::createPropertyMap):
(JSC::Structure::getPropertyNames):
(JSC::PropertyTable::checkConsistency):
(JSC::Structure::checkConsistency):
    factored out code to PropertyMapHashTable.h
* runtime/Structure.h:
(JSC::Structure::propertyStorageSize):
(JSC::Structure::isEmpty):
(JSC::Structure::get):
    factored out code to PropertyMapHashTable.h

../JavaScriptGlue: 

* ForwardingHeaders/wtf/HashTable.h: Added.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@79963 268f45cc-cd09-0410-ab3c-d52691b4dbfc