Disable optimization for functions that have scopes that cannot be reconstructed from the context chain. (issue 2071)

Define V8_EXPORT to nothing for clients of v8. (Chromium issue 90078)

Correctly check for native error objects.  (Chromium issue 2138)

Performance and stability improvements on all platforms.

git-svn-id: http://v8.googlecode.com/svn/trunk@11594 ce2b1a6d-e550-0410-aec6-3dcde31c8c00