[Bug tree-optimization/92765] [10 Regression] Wrong code caused by folding of -Wstring-compare since r276773

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92765

--- Comment #12 from Martin Sebor <msebor at gcc dot gnu.org> ---
The __builtin_strcmp(ptr->header.magic, "x") call in comment #0 is undefined
because the two-element array ptr->header.magic is not a nul-terminated string.
 The warning was designed to point that out.

Removing the call removes the bug from the test case and lets it run to
completion.