Make breakpoints on == fire reliably

Add breakpoints in the path taken if one of the operands
in a == b is null.

R=asiva@google.com

Review URL: https://codereview.chromium.org//14991010

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@22857 260f80e4-7a28-3924-810f-c04153c831b5
14 files changed