convert BitVector to use pointer size blocks

convert BitVector to use pointer size blocks

additionally rename data-flow.* to bit-vector.* as at some point these file became very inaccurately named

BUG=
R=svenpanne@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=25030

[Sven Panne, 2014-10-31 10:18:54]

svenpanne@chromium.org changed reviewers:
+ svenpanne@chromium.org

[Sven Panne, 2014-10-31 10:18:54]

LGTM when the Win64 issue is fixed.

https://codereview.chromium.org/683243005/diff/1/src/data-flow.cc
File src/data-flow.cc (right):

https://codereview.chromium.org/683243005/diff/1/src/data-flow.cc#newcode50
src/data-flow.cc:50: count += base::bits::CountPopulation64(data);
Not really related to your CL, but I think we should templatize the Foo32/Foo64
stuff in base::bits.

The "data != 0" is a (premature?) optimization, so the body of the loop should
simply look like:

   count += base::bits::CountPopulation(data_[i]);

[dcarney, 2014-10-31 10:44:22]

Committed patchset #3 (id:40001) manually as 25030 (presubmit successful).