Unfortunately, the Go x86 syntax has a lot of weird names, inconsistencies, and problems.
As already mentioned in the comments, MOVOU is MOVDQU.
, , .
AVX512 , .
, ctrl+F Go asm.
:

x86.v0.2.csv, Intel, GNU Go .
v0.2 , .
, aliases, , , PADDD PADDL,
- - .
, , Go asm "". , , N .
"" .
( , , Russ Cox : issue21528.)