[release-branch.go1.22] cmd/link: handle dynamic import variables on Darwin in plugin mode
CL 501855 added support for cgo_dynamic_import variables on Darwin.
But it didn't support the plugin build mode on amd64, where the
assembler turns a direct load (R_PCREL) to a load via GOT
(R_GOTPCREL). This CL adds the support. We just need to handle
external linking mode, as this can only occur in plugin or shared
build mode, which requires external linking.
Fixes #68122.
Updates #67976.
Updates #50891.
Change-Id: I0f56265d50bfcb36047fa5538ad7a5ec77e7ef96
Reviewed-on: https://go-review.googlesource.com/c/go/+/592499
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
(cherry picked from commit
44f18706661db8b865719d15a5cfa0515d1a4fca)
Reviewed-on: https://go-review.googlesource.com/c/go/+/595175
Reviewed-by: Joedian Reid <joedian@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>