Update AVXFMA4 noise implementation (#268)
Update AVXFMA4 noise implementation (#268)

Improved performance and code readability. The changes only affect AMD parts with FMA4 support.
wfpokorny/povray,wfpokorny/povray,POV-Ray/povray,BentSm/povray,LeForgeron/povray,c-lipka/povray,POV-Ray/povray,LeForgeron/povray,wfpokorny/povray,POV-Ray/povray,LeForgeron/povray,eblanca/povray,wfpokorny/povray,BentSm/povray,POV-Ray/povray,eblanca/povray,LeForgeron/povray,BentSm/povray,POV-Ray/povray,LeForgeron/povray,c-lipka/povray,eblanca/povray,POV-Ray/povray,c-lipka/povray,c-lipka/povray,LeForgeron/povray,wfpokorny/povray,wfpokorny/povray,LeForgeron/povray,wfpokorny/povray,POV-Ray/povray,eblanca/povray,LeForgeron/povray,BentSm/povray