[NFC] Parallelize the actual inlining part of the Inlining pass (#6966)

We already parallelized collecting info about functions and finding
inlining opportunities, but the actual inlining - copying the code into
the target function - was done sequentially. It turns out that a lot of
work happens there: this PR makes the pass over 2x faster.

Details:
* Move nameHint to InliningAction, so it is there when we apply the
  actions.
* Add a DoInlining internal pass which calls doInlining().
* Refactor OptUtils a little to make it easy to run DoInlining before
  opts.
 * Also remove the return value of doInlining which was not used.

0 files changed, 0 insertions, 0 deletions