SingletonLogger::LogMessage did not work as advertised and
overwrote existing message.

R=mstarzinger@chromium.org
BUG=v8:2220
TEST=test-parsing/PreparserStrictOctal

Review URL: https://chromiumcodereview.appspot.com/10689134

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12031 ce2b1a6d-e550-0410-aec6-3dcde31c8c00