lang/go122: fix build on armv7

This backports a commit needed to get proper barriers during bootstrap
when building Go with more than one job on armv7.

Note that this only changes the behaviour when building the bootstrap
toolchain. Binaries generated using the toolchain are not affected
and hence Go ports need not be bumped.

PR: 278953
Approved by: portmgr (build fix blanket)
Obtained from: https://go-review.googlesource.com/c/go/+/562995
See also: https://github.com/golang/go/issues/65601
MFH: 2024Q2