Generate StoreGlobal stubs with Hydrogen

- Constants globals are inlined into Hydrogen code using code dependencies that invalidate the Crankshafted code when global PropertyCells or the global object change.
- The more general case generates code that is just as good as the hand-written assembly stubs on all platforms.

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/16925008

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15419 ce2b1a6d-e550-0410-aec6-3dcde31c8c00