Re: Annoying build warnings from latest Apple toolchain

I wrote:
> Andres Freund <andres(at)anarazel(dot)de> writes:
>> On 2023-09-28 16:46:08 -0400, Tom Lane wrote:
>>> Well, it's only important on platforms where we can't restrict
>>> libpq.so from exporting all symbols. I don't know how close we are
>>> to deciding that such cases are no longer interesting to worry about.
>>> Makefile.shlib seems to know how to do it everywhere except Windows,
>>> and I imagine we know how to do it over in the MSVC scripts.

>> Hm, then I'd argue that we don't need to care about it anymore. The meson
>> build does the necessary magic on windows, as do the current msvc scripts.

> If we take that argument seriously, then I'm inclined to adjust my
> upthread patch for Makefile.global.in so that it removes the extra
> inclusions of libpgport/libpgcommon everywhere, not only macOS.
> The rationale would be that it's not worth worrying about ABI
> stability details on any straggler platforms.

Looking closer, it's only since v16 that we have export list support
on all officially-supported platforms. Therefore, I think the prudent
thing to do in the back branches is use the patch I posted before,
to suppress the duplicate -l switches only on macOS. In HEAD,
I propose we simplify life by doing it everywhere, as attached.

regards, tom lane