Patch by Geoffrey Garen <ggaren@apple.com> on 2009-08-20
Reviewed by Maciej Stachowiak.

1.07x faster on v8 (1.7x faster on v8-splay).
1.004x faster on SunSpider.

* runtime/JSCell.h: Moved JSValue::toString to JSString.h.
* runtime/JSGlobalData.h: Holds the cache.
* runtime/JSNumberCell.cpp:
(JSC::JSNumberCell::toString):
(JSC::JSNumberCell::toThisString): Removed -0 special case.
UString handles this now, since too many clients were
special-casing it.

* runtime/JSString.h:
(JSC::JSValue::toString): Use the cache when converting
an int or double to string.

* runtime/Operations.h:
(JSC::concatenateStrings): Call toString to take advantage
of the cache.

* runtime/SmallStrings.h:
(JSC::NumericStrings::add):
(JSC::NumericStrings::lookup): The cache.

* runtime/UString.cpp:
(JSC::UString::from): Added -0 special case mentioned above.
Removed appendNumeric because it's mutually exclusive with the
cache.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@47622 268f45cc-cd09-0410-ab3c-d52691b4dbfc