cmd/compile, cmd/dist, internal: enable buildmode=pie for linux/loong64
This is actually not tied to the ELF psABI v2 upgrade, and can be
enabled "for free".
Change-Id: I6906d9eb4bd8655c685b059283e200cb7e210369
Reviewed-on: https://go-review.googlesource.com/c/go/+/455075
Reviewed-by: abner chenc <chenguoqi@loongson.cn>
Run-TryBot: Ben Shi <powerman1st@163.com>
Reviewed-by: Meidan Li <limeidan@loongson.cn>
Run-TryBot: WANG Xuerui <git@xen0n.name>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: David Chase <drchase@google.com>