increase in SUBBUCKETS has performance impact

[impact]

a negative performance impact is found with the increase in SUBBUCKETS

[test case]

TBD

[regression potential]

any regression would likely cause performance issues

[scope]

this is needed only for golang 1.14 and 1.15; the patch is not added in 1.13 or earlier, nor in 1.16.

Specifically, this is needed in f/g/h in the specific golang versions as shown:

$ grep -E 'SUBBUCKETS += 32' */*/golang-*/src/cmd/link/internal/ld/pcln.go
golang-1.14/focal/golang-1.14-1.14.3/src/cmd/link/internal/ld/pcln.go: SUBBUCKETS = 32
golang-1.14/groovy/golang-1.14-1.14.7/src/cmd/link/internal/ld/pcln.go: SUBBUCKETS = 32
golang-1.14/hirsute/golang-1.14-1.14.7/src/cmd/link/internal/ld/pcln.go: SUBBUCKETS = 32
golang-1.15/hirsute/golang-1.15-1.15.8/src/cmd/link/internal/ld/pcln.go: SUBBUCKETS = 32

[other info]

this was added to golang-1.14 with the patch:
debian/patches/0001-cmd-link-add-support-for-external-linking-on-linux-r.patch
and golong-1.15 with the similar patch:
debian/patches/fc3e6af10297b424175b44d2274de04c5f0b9e82.patch

There does not appear to be any documentation or explanation for why the patch modifies SUBBUCKETS.

Upstream, this appears to have been done with the commit 15eaa870e14195c17dbb4be0d11bc40dba94ff22, which does not change SUBBUCKETS.