[vala] (10 commits) Non-fast-forward update to branch wip/abi

[Rico Tzschichholz <ricotz src gnome org>]

The branch 'wip/abi' 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:

  11897b4... compiler: Add --abi-stability option for future ABI stabili
  4ad3386... ccode: Allow adding of comments to a CCodeStruct
  5a2f5ef... codegen: Add public/private separator comments to type/inst
  0d700a1... codegen: Add "padding" CCode attributes for classes/interfa
  dae8649... tests: Add second pass with --abi-stability
  3121a88... codegen: Add abi-stability path for classes
  067bf62... codegen: Add abi-stability path for interfaces

Commits added to the branch:

  5573992... Revert "Do not warn about non-default parameters for corout (*)
  70e694d... vala: Skip default-value positioning check for parameters o (*)
  71ffab1... tests: Add test for parameter type checking of async method (*)
  95de051... compiler: Add --abi-stability option for future ABI stabili (*)
  43a5692... codegen: Add abi-stability path for classes (*)
  07528ea... codegen: Add abi-stability path for interfaces (*)
  e8a656b... codegen: Add "padding" CCode attributes for classes/interfa
  09b9acc... tests: Add second pass with --abi-stability
  a393e07... ccode: Allow adding of comments to a CCodeStruct
  57dd5e4... codegen: Add public/private separator comments to type/inst

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