Rebase onto 4.4 to support new ˋ--shuffleˋ option

[echoix]

Since GNU Make 4.4, a new option ˋ--shuffleˋ was introduced. It helps pointing out errors in missing dependencies by intentionally reordering jobs to do while still respecting the constraints of a Makefile. So rare-to-find issues that only occur with big parallel builds and when some jobs take abnormally a different time that causes a change in order, become evident really easily, for me in the first run.

See:
https://trofi.github.io/posts/238-new-make-shuffle-mode.html
https://trofi.github.io/posts/249-an-update-on-make-shuffle.html
https://trofi.github.io/posts/294-an-obscure-make-shuffle-bug.html
https://www.gnu.org/software/make/manual/html_node/Options-Summary.html

But now that I found remake, with its profiling output, and the nice trace output, it's a difficult choice to make to chose either one or the other. Considering that remake seems to be targetted to be a tool to enhance gnu make in order to debug weird issues, or to use its debugger, I think that rebasing to 4.4 brings a useful feature and seems worth it ;)

I read the wiki entry that explained the manual rebasing process, it seems too complicated for me to follow through.