The catch variable is bound in the catch scope.  For simplicity in this
initial implementation, it is always allocated even if unused and always
allocated to a catch context even if it doesn't escape.  The presence of
catch is no longer treated as a with.

In this change, care must be taken to distinguish between the scope where a
var declaration is hoisted to and the scope where the initialization occurs.

R=ager@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/7280012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8496 ce2b1a6d-e550-0410-aec6-3dcde31c8c00