[Bug c/98269] gcc 6.5.0 __builtin_add_overflow() with small uint32_t values incorrectly detects overflow

[stli at linux dot ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98269

--- Comment #5 from stli at linux dot ibm.com <stli at linux dot ibm.com> ---
Just as information,
I've just committed this glibc patch:
"s390x: Require GCC 7.1 or later to build glibc."
https://sourceware.org/git/?p=glibc.git;a=commit;h=844b4d8b4b937fe6943d2c0c80ce7d871cdb1eb5