cmd/link: put shlib ".type" functions in internal ABI
These functions are compiler generated, and as such are only available
in the internal ABI. Doing this avoids generating an alias symbol.
Doing that avoids confusion between unmangled and mangled type symbols.
Fixes #30768
Change-Id: I197a5ba6403aac11989ffa951dbe35bd0506de91
Reviewed-on: https://go-review.googlesource.com/c/go/+/186077
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>