Fixed a bug in abrupt exit from with or catch inside finally.

Fixed possible crash in FixedDoubleArray::Initialize() (Chromium issue 95113).

Fixed a bug in Page::GetRegionMaskForSpan (Chromium issue 94425).

Fixed a few clang warnings (which -Werror treated as errors).

Performance improvements on all platforms.

git-svn-id: http://v8.googlecode.com/svn/trunk@9173 ce2b1a6d-e550-0410-aec6-3dcde31c8c00