Cache maps when normalizing properties....

Cache maps when normalizing properties.

Not for commit.
 
I am unsure about whether the cache should be global (as ContextSlotCache)
or per-context. I am inclined towards per-context as the information in
the cache is context-dependent, and multiple contexts would cause more
hash collisions.

Unfinished:
- some constants hardcoded
- no pre-compact cleanup

[Mads Ager (chromium), 2010-07-23 09:07:32]

I would also go for a context specific cache to limit the number of collisions.

I don't know if all of the xors in the hash function makes sense. Maybe we can
make it simpler and still get something decent.

http://codereview.chromium.org/3028019/diff/1/4
File src/objects.cc (right):

http://codereview.chromium.org/3028019/diff/1/4#newcode2117
src/objects.cc:2117: class NormalizedMapCache {
: public AllStatic ?

Also, please have public: section before private:.

http://codereview.chromium.org/3028019/diff/1/4#newcode2154
src/objects.cc:2154: return index & 0xFF;
Why do you return only 8 bits?