Fix Function::Clone() and Field::Clone() to adjust the class owner of type
parameters (issue 18630).
Add regression tests.
Commented out 3 lines in mirror test (issue 21474 filed).

R=srdjan@google.com

Review URL: https://codereview.chromium.org//646103005

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41424 260f80e4-7a28-3924-810f-c04153c831b5
Revert mixin fix r41424 until mirrors issue 21474 is fixed.

Review URL: https://codereview.chromium.org//691053004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41425 260f80e4-7a28-3924-810f-c04153c831b5