Changing the aging mechanism for script and eval caches.

Changing the aging mechanism for script and eval caches.
Instead of using multiple generations for the code, first only store the hash that gets aged. Once a hash matched on a next probe, actually cache the code. Use regular code aging to remove entries from the cache.

BUG=
R=ulan@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=25040

[Toon Verwaest, 2014-10-29 16:47:57]

verwaest@chromium.org changed reviewers:
+ ulan@chromium.org

[Toon Verwaest, 2014-10-29 16:47:58]

PTAL

[ulan, 2014-10-30 09:25:49]

Looking good. Please add tests for:
- compilation cache doesn't keep SFI and code alive after N GCs,
- Put(x); Lookup(x) == undefined;
- Put(x); Put(x); Lookup(x) == x;
- Put(x); 10 * Age(); Put(x); Lookup(x) == undefined;

https://codereview.chromium.org/675013004/diff/20001/src/objects.h
File src/objects.h (right):

https://codereview.chromium.org/675013004/diff/20001/src/objects.h#newcode7940
src/objects.h:7940: class CompilationCacheTable: public
HashTable<CompilationCacheTable,
Could you please add few words describing state changes of (key, value) entry
with put, age, and lookup operations?

[ulan, 2014-10-31 14:44:48]

lgtm

[Toon Verwaest, 2014-10-31 14:51:58]

Committed patchset #4 (id:60001) manually as 25040 (presubmit successful).