Re: BUG #16920: Can't compile PostGIS with MingW64 against PostgreSQL 14 head

I wrote:
> Hmm, interesting.  The gcc manual is quite negative about these though:
> https://gcc.gnu.org/onlinedocs/gcc/Nonlocal-Gotos.html
> Also it's not clear that these are compatible with <setjmp.h>'s version
> of jmp_buf.

After further study, I think we could fix the jmp_buf inconsistency as
attached.

I did some googling and found that we'd be in pretty good company if
we go this way: a lot of other projects have concluded that MinGW-64's
setjmp() is hopelessly buggy and adopted this same workaround.  It still
makes me a bit nervous though, as this is a serious ABI break for
anything using setjmp/longjmp.  We could not back-patch such a change,
and once we ship a release using this we're stuck with it in that
release branch.

Regina, could you confirm whether this fixes things for you?

			regards, tom lane