[Bug tree-optimization/108860] [12/13 regression] New (since gcc 12) false positive null-dereference in vector.resize

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108860

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This fixes it for GCC 14, but I'm not sure why the compiler can't tell this
isn't true already:

--- a/libstdc++-v3/include/bits/vector.tcc
+++ b/libstdc++-v3/include/bits/vector.tcc
@@ -833,6 +833,9 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
                _M_check_len(__n, "vector::_M_default_append");
              pointer __new_start(this->_M_allocate(__len));

+             if (!__new_start)
+               __builtin_unreachable();
+
              // RAII guard for allocated storage.
              struct _Guard
              {