There was a risk of a race condition between encoding tasks on the output array.
It could be that two task compete in writing a word at the border of their respective segment groups.
This commit offers to solve this issue by retaining the tail word in a struct that is returned after task completion so that segment group border can be fixed after completion of all the tasks.
Comes with additional cleanups of nrLDPC_coding_segment_encoder:
1. Move the section of code dedicated to writing to the encoding library output to a separate function.
2. Remove bit interleave debug in AVX512VBMI case of output writing for improving code readability.
Romain Beurdouche
b1e1c161ec