Follow the reference implementation more closely

There is no Julia equivalent for this code, and we want to run on all
cores anyways, so just let OpenMP do its thing

No Denglish anymore

This has two reasons:
	- It already has to be done like this for C++
	- flang doesn't implement the OpenMP reduction operation yet

This reverts commit 0e1919cd.

This makes the code simpler and it is closer to what the other programs
(including the reference) already do.