Avoid constructing types with errors.

BUG=27626735

Rationale:
Do not construct classes with a link error. Without this,
the error type thought it was Object (mirror's method
IsObjectClass() returns true if there is no superclass).

(cherry picked from commit 8b3f9b24)
(also contains follow-up commit 31244b4c)

Change-Id: I4443779dda47c320115975c1c71b22e118bd8252