Merge remote-tracking branch 'upstream-gccrs/master' into dkm/master-rebased

This branch has a no-op merge as the last commit:

 - one arm is the "current" development branch from github
 - the other arm is a rebased version of the "current" master branch onto a recent GCC's master

The merge is obtained with "git merge --strategy=ours" to only keep the changes from second arm.

Author: dkm