Reapply: Never use classic code generator.

Reapply: Never use classic code generator.

Crankshaft is now the default on all platforms. This is the first
patch on the way to removing the classic code generator from the
system.

This time with no removal of the crankshaft flag. --nocrankshaft is
not at all the same as --always-full-compiler which I had used instead
for testing. That was what caused timeouts on the buildbots because of
repeated attempts to optimize hot functions. It makes sense to keep
the crankshaft flag in case you want to run only with the full
compiler and with no adaptive compilation.

R=vitalyr@chromium.org

Review URL: http://codereview.chromium.org/6759070

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7486 ce2b1a6d-e550-0410-aec6-3dcde31c8c00