[vala] (5 commits) Non-fast-forward update to branch wip/issue/1062

[Rico Tzschichholz <ricotz src gnome org>]

The branch 'wip/issue/1062' 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:

  973c0e7... vala: Set parent_node for child nodes of lambda-expression

Commits added to the branch:

  48f9982... Add TraverseVisitor for traversing the tree with a callback (*)
  647b55d... vala: Move transformation of unary increment/decrement to c (*)
  cb1828c... Force usage of temporary variables for "tainted" member acc (*)
  8bab9d1... tests: Add "pre-post-increment with side effect" tests to i (*)
  254431c... vala: Set parent_node for child nodes of lambda-expression

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