Merged r17620, r17621 into trunk branch.

Fix potential assertion failure in ConvertCase.

Fix potential assertion failure.

BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/66513006

git-svn-id: https://v8.googlecode.com/svn/trunk@17623 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Version 3.23.2

Fixed --extra-code flag for snapshot creation. (issue 2994)

Fixed error message wording when instanceof throws. (Chromium issue 82797, issue 1593)

Performance and stability improvements on all platforms.

git-svn-id: https://v8.googlecode.com/svn/trunk@17630 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Merge remote-tracking branch 'upstream/trunk' into trunk