cmd/compile: simplify func value symbol generation
Currently, in most cases the compiler generates a func value
symbol when it is referenced, except when building a shared object
it generates the func value symbol when the function is declared.
The comment says this was necessary because we cannot deduplicate
DUPOK symbols across DSO boundaries. But the dynamic linker is
just fine to resolve symbols with the same name across DSO
boundaries.
Another problem may be that the address of the PLT stub may be
used. When such a func value is deferred, when the runtime needs
to scan its arguments, it cannot look up the PC to find the
function and therefore cannot find its stack map. This is not a
problem now as deferred functions always have no arguments.
Remove the special case for shared linkage.
Change-Id: Id7df0b0ada6d3d7f85741a9ab09581975509516c
Reviewed-on: https://go-review.googlesource.com/c/go/+/396534
Trust: Cherry Mui <cherryyz@google.com> Reviewed-by: Than McIntosh <thanm@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>