Use C++11 static_assert() if available.

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/19684009

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15736 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Just check for C++ version.

This fixes build breakage introduced with r15736.

TBR=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/19671009

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15737 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Handlify JSFunction::SetPrototype method.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/19594002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15738 ce2b1a6d-e550-0410-aec6-3dcde31c8c00