Find breakpoint by PC rather than source position when clearing breakpoint
Current approach is to find breakpoint by the statement position that was used when setting breakpoint. This doesn't work when setting breakpoint by anything else but statement position.
(Question: could PC of existing breakpoint change, for example because of recompilation, or this approach is safe)
R=yangguo@chromium.org
Review URL: https://codereview.chromium.org/
15685010
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15021
ce2b1a6d-e550-0410-aec6-
3dcde31c8c00