[vala] (9 commits) Non-fast-forward update to branch wip/issue/278

[Rico Tzschichholz <ricotz src gnome org>]

The branch 'wip/issue/278' 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:

  079cd62... Add supported for sealed classes
  ac3217b... WIP

Commits added to the branch:

  7850210... vala: Infer target_type in coalescing expressions (*)
  6cfa112... vala: Non-nullable value-type in coalesce expression needs  (*)
  6f673c2... vala: Fix short-circuiting behavior of coalescing operator (*)
  ea07220... parser: Extend source_reference of parenthesized expr to co (*)
  8dd348c... codegen: Use result value of assignment rather than its com (*)
  8021ad3... glib-2.0: Let (u)int.try_parse() return false if there is a (*)
  98ab3da... Add further support for params arrays (*)
  d77c719... Add supported for sealed classes
  20ecc27... WIP

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