[Bug target/111722] manually defined memcpy() and memmove() incorrectly handle overlap with -O2 -m32 -march=bdver2

[zfigura at codeweavers dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111722

--- Comment #3 from Zeb Figura <zfigura at codeweavers dot com> ---
Created attachment 56072
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56072&action=edit
testcase

Attaching a reduced-ish testcase, that contains the unmodified code of memcpy()
and memmove(), plus two callers. The callers seem to be necessary to trigger
the incorrect optimization.

Compile with '-c -O2 -march=bdver2 -m32'.