Fix special handling of DefineOwnProperty on arrays.

Fix special handling of DefineOwnProperty on arrays.

According to the ES5 spec the implementation of DefineOwnProperty() has
to special case handling of arrays. This implementation correctly
handles definitions of array index properties and redefinitions of the
length property.

R=svenpanne@chromium.org
BUG=v8:1756
TEST=test262

Committed: http://code.google.com/p/v8/source/detail?r=10149

[Michael Starzinger, 2011-12-02 16:13:06]

PTAL. This re-lands an improved version of
http://codereview.chromium.org/8221002.

[danno, 2011-12-02 16:24:46]

lgtm

[Sven Panne, 2011-12-05 09:38:14]

lgtm