cmd/cgo: fix unaligned arguments typedmemmove crash on iOS
Irregularly typedmemmove and bulkBarrierPreWrite crashes on unaligned
arguments. By aligning the arguments this is fixed.
Fixes #46893
Change-Id: I7beb9fdc31053fcb71bee6c6cb906dea31718c56
GitHub-Last-Rev:
46ae8b96889644aab60ea4284cf447a740354c6a
GitHub-Pull-Request: golang/go#74868
Reviewed-on: https://go-review.googlesource.com/c/go/+/692935
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>