Split refactoring problems into init, options and final.

Split refactoring problems into init, options and final.

R=brianwilkerson@google.com, jwren@google.com
BUG=

Committed: https://code.google.com/p/dart/source/detail?r=40318

[jwren, 2014-09-16 06:37:22]

On 2014/09/16 03:40:59, scheglov wrote:

LGTM

[Brian Wilkerson, 2014-09-16 13:57:23]

LGTM

[scheglov, 2014-09-16 14:27:12]

If we search for B.m, then it should return a.m(1) (and b.m(2) too), but not
c.m(3) even though they resolve to the same A.m.
The reason is that "c" cannot be B (in the checked mode), so you cannot call B.m
using it.

So, we need to record target types and use it later to filter out incompatible
matches.

A {
  m(_) {}
}
B extends A {
  m(_) {}
}
C extends A {}

main(A a, B b, C c) {
  a.m(1);
  a.m(2);
  a.m(3);
}

[scheglov, 2014-09-16 15:15:00]

Committed patchset #1 (id:1) manually as 40318 (presubmit successful).