cmd/link: mangle certain instantiated function name in plugin mode
In plugin mode, we mangle the type symbol name so it doesn't
contain characters that may confuse the external linker. With
generics, instantiated function name includes type names, so it
may also contain such characters and so also needs to be mangled.
Fixes #58800.
Change-Id: Ibb08c95b89b8a815ccef98193d3a025e9d4756cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/500095 Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Cherry Mui <cherryyz@google.com>