Make Array.prototype.pop throw if the last element is not configurable.

Make Array.prototype.pop throw if the last element is not configurable.
Popping an element from an array should call [[Delete]] internal method
and pass true as the second argument (ECMA-262/5.1/#sec-15.4.4.6).
When the last element can't be deleted, throw a Type Error.
Not throwing the error would result in endless loop in the following test.

TEST=var a=[];Object.defineProperty(a,0,{});while(a.length)a.pop();

By the way fix another bug, or else i can't post any issues.
"presubmit.py" throw a "missing a correct copyright header" on windows.
Both the slash and the backslash are valid path separator on windows.

R=yangguo@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=17346

[Yang, 2013-10-23 08:25:47]

On 2013/10/19 03:45:25, Yanagi wrote:

LGTM. I'll land this after making sure that there is no impact on performance.

[Yang, 2013-10-23 08:25:54]

https://codereview.chromium.org/29513004/diff/30001/tools/presubmit.py
File tools/presubmit.py (right):

https://codereview.chromium.org/29513004/diff/30001/tools/presubmit.py#newcod...
tools/presubmit.py:295: for dir_part in
os.path.dirname(file).replace(os.sep,'/').split('/'):
I took the liberty to change this to .dirname(file).split(os.sep)

[Yang, 2013-10-23 16:14:23]

https://codereview.chromium.org/29513004/diff/30001/tools/presubmit.py
File tools/presubmit.py (right):

https://codereview.chromium.org/29513004/diff/30001/tools/presubmit.py#newcod...
tools/presubmit.py:295: for dir_part in
os.path.dirname(file).replace(os.sep,'/').split('/'):
On 2013/10/23 08:25:54, Yang wrote:
> I took the liberty to change this to .dirname(file).split(os.sep)

nvm this.

[Yang, 2013-10-23 16:19:33]

Committed patchset #1 manually as r17346 (presubmit successful).