Make EvictFromOptimizedCodeMap more robust.

Make EvictFromOptimizedCodeMap more robust.

This removes all occurences of the specified optimized code from the optimized
code map.

R=titzer@chromium.org, yangguo@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=19638

[ulan, 2014-03-03 12:24:14]

PTAL. Most of the code is from r19603, but instead of checking for context
equality it now checks for code equality.

This addresses Ben's comments from https://codereview.chromium.org/184923002:
> titzer 2014/03/03 12:02:44
> This code is relying on the code appearing only once in this optimized code
map,
> which is an invariant that should hold, but based on my investigation, looks
> quite fragile.

> Can we put an extra level of checking in this loop?

> I.e. either go through the entire map and remove _all_ occurrences, or assert
> there is only one.

> I would prefer the former, since we have to loop over the entire array anyway,
> even if we found it.

[Yang, 2014-03-03 12:26:35]

On 2014/03/03 12:24:14, ulan wrote:
> PTAL. Most of the code is from r19603, but instead of checking for context
> equality it now checks for code equality.
> 
> This addresses Ben's comments from https://codereview.chromium.org/184923002:
> > titzer 2014/03/03 12:02:44
> > This code is relying on the code appearing only once in this optimized code
> map,
> > which is an invariant that should hold, but based on my investigation, looks
> > quite fragile.
> 
> > Can we put an extra level of checking in this loop?
> 
> > I.e. either go through the entire map and remove _all_ occurrences, or
assert
> > there is only one.
> 
> > I would prefer the former, since we have to loop over the entire array
anyway,
> > even if we found it.

LGTM.

[titzer, 2014-03-03 12:41:30]

lgtm

[ulan, 2014-03-03 13:12:38]

Committed patchset #2 manually as r19638 (tree was closed).