cmd/internal/obj: add tool to generate Cnames string
Add cmd/internal/obj/mkcnames.go to do the generation and update
the architecture packages to use it to maintain the Cnames tables.
Currently works correctly on arm64,loong64,mips,ppc64 and s390x.
Change-Id: I5220b0ba6d8a8a5fcc4d9774731eb2af69a671af
Reviewed-on: https://go-review.googlesource.com/c/go/+/622256 Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Meidan Li <limeidan@loongson.cn>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Qiqi Huang <huangqiqi@loongson.cn>
Auto-Submit: Ian Lance Taylor <iant@golang.org> Reviewed-by: sophie zhao <zhaoxiaolin@loongson.cn>
Commit-Queue: Ian Lance Taylor <iant@golang.org>