[vala] (5 commits) Non-fast-forward update to branch wip/issue/911

[Rico Tzschichholz <ricotz src gnome org>]

The branch 'wip/issue/911' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  070c81c... WIP vala: Improve dealing with errornous nodes

Commits added to the branch:

  169b990... vala: Don't check for unhandled error if error is set on bo (*)
  1f51967... vala: Properly set CodeNode.error when reporting an error ( (*)
  98fd2b1... vala: Don't analyze error-type of errornous catch-clauses (*)
  4f48a27... vala: Handle unavailable type-symbol in Constant.check_cons (*)
  e590725... vala: Skip UsingDirective if error is set (*)

(*) This commit already existed in another branch; no separate mail sent