Splitting breakpoints into SourceBreakpoint that represent
a user-defined source location of a breakpoint, and
CodeBreakpoint, which represents a code location. There can
be more than one CodeBreakpoint per SourceBreakpoint, e.g.
for functions that are also called as closures (and are thus
compiled twice.)
Functions are no longer compiled as a side effect of setting
a breakpoint. When they eventually get compiled, the previously
recorded SourceBreakpoint is found and a CodeBreakpoint is set.
Review URL: https://chromiumcodereview.appspot.com//9581013
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@4891 260f80e4-7a28-3924-810f-c04153c831b5