Check string literals with escapes in PreParserTraits::GetSymbol()

LOG=Y
BUG=v8:3606
R=arv@chromium.org, marja@chromium.org

Review URL: https://codereview.chromium.org/615813004

Patch from Caitlin Potter <caitpotter88@gmail.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24880 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix "jst" GDB macro

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/669383002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24881 ce2b1a6d-e550-0410-aec6-3dcde31c8c00