[Bug middle-end/115767] [11/12/13/14/15 regression] GCC loses track of value on aarch64 with -O2

[bugs at qult dot net via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115767

--- Comment #5 from Ignacy Gawędzki <bugs at qult dot net> ---
FWIW, I ran a git bisect from releases/gcc-10.5.0 to releases/gcc-11.1.0 and
the first bad commit is d119f34c952f8718fdbabc63e2f369a16e92fa07, which adds
modref/ipa_modref optimization passes.