Don't count duplicate assignments to the same property as distinct ones.

Don't count duplicate assignments to the same property as distinct ones.

In the ThisNamedPropertyAssignmentFinder, duplicate assignments to the same
property were counted as distinct assignments.  As a simple fix, subsequent
ones overwrite the previously recorded assignment.

This will reorder the assignments, but it is safe since they are restricted
to have only constants and parameters on the right-hand side (and there are
no assignments to the parameters).

R=vegorov@chromium.org
BUG=
TEST=

Committed: http://code.google.com/p/v8/source/detail?r=9540

[Kevin Millikin (Chromium), 2011-10-05 18:01:34]

I have a reduced test for this, but it requires concatenating two different test
files.

Perhaps we can work on finding a way to test it tomorrow.

[Vyacheslav Egorov (Chromium), 2011-10-05 18:27:52]

LGTM