Switch scheduler to iterative floating control placement.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/685773002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24968 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Add performance tests for Map/Set with String and Object keys

The big change here is to split out each key type into its own
benchmark suite, since optimizations for different key types
are likely to be disjoint. ForEach tests have also been split
into separate "Iteration" suites, again with the thought that
iteration performance is likely separable from key type.

As part of adding the new tests, rejiggered the existing tests:
  - Map.set and Set.add (along with their Weak variants) no longer
    include construction costs in their scores
  - Moved key logic into the shared common.js

R=arv@chromium.org, machenbach@chromium.org

Review URL: https://codereview.chromium.org/685753004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24969 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Reland "In PrepareForBreakPoints, also purge shared function info not referenced by functions."

BUG=chromium:424142
LOG=N
R=jarin@chromium.org

Review URL: https://codereview.chromium.org/692453002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24970 ce2b1a6d-e550-0410-aec6-3dcde31c8c00