https://bugs.webkit.org/show_bug.cgi?id=110560

Reviewed by Antti Koivisto.

(*) 5% PLT arithmetic mean speedup
(*) 10% PLT geometric mean speedup
(*) 3.4X microbenchmark speedup
(*) Reduces initial cache capacity by 16X

* runtime/CodeCache.cpp:
(JSC::CodeCache::CodeCache): Updated for interface change.

* runtime/CodeCache.h:
(JSC::SourceCodeValue::SourceCodeValue):
(SourceCodeValue): Turned the cache value into a struct so it can track its age.

(CodeCacheMap):
(JSC::CodeCacheMap::CodeCacheMap):
(JSC::CodeCacheMap::find):
(JSC::CodeCacheMap::set):
(JSC::CodeCacheMap::clear):
(JSC::CodeCacheMap::pruneIfNeeded):
(CodeCache): Grow and shrink in response to usage.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@143759 268f45cc-cd09-0410-ab3c-d52691b4dbfc