Extract the part of SetPropertyForResult that searches the prototype chain
for accessor setters into a separate function SetPropertyInPrototypes.
Call this function in SetPropertyPostInterceptor.

This should fix both optimized and unoptimized cases because
the cache stub for storing with interceptor calls the runtime system.

BUG=v8:1636

TEST=cctest/test-api.cc/EmptyInterceptorDoesNotShadowAccessors

Review URL: http://codereview.chromium.org/7991007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9431 ce2b1a6d-e550-0410-aec6-3dcde31c8c00