[Sheriff] This reverts commits r21225 and r21226 for breaking Linux64 build.

Revert "Make BitField3 a raw uint32 field, and move to the start of the map."
Revert "Make space available in bf3 by moving FunctionWithPrototype to bf1"

TBR=verwaest@chromium.org

Review URL: https://codereview.chromium.org/278883002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21227 ce2b1a6d-e550-0410-aec6-3dcde31c8c00