atomic in i386 Current after CLANG 6 upgrade

[Luca Pizzamiglio]

Hy all,

I've already received a couple of messages from pkg-fallout about build
failure on head-i386-default [1] [2] both pointing to the same errors,
about missing intrinsic symbols related to __atomic_*

The clang documentation about C11 atomic builtins [3] stats that __atomic_*
are GCC extension and Clang provides them.

It seems to me that this specific GCC-compatible builtin are enabled on
amd64, but not on i386.
Is there a way to enable GCC compatible __atomic_ builtin also on i386?
Or should I provide patches to adopt _c11_atomic_* instead of __atomic_*
for every ports that need it ?

Thanks in advance!
Best regards,
pizzamg

[1]
http://beefy11.nyi.freebsd.org/data/head-i386-default/p458948_s327953/logs/librdkafka-0.11.3.log
[2]
http://beefy11.nyi.freebsd.org/data/head-i386-default/p458948_s327953/logs/stress-ng-0.09.09.log
[3] https://clang.llvm.org/docs/LanguageExtensions.html#langext-c11-atomic