[Bug ipa/103875] Dead writes are not optimized out

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103875

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
The clobber is gone at the point we inline pop(), CDDCE1 removes it because
the clobbered address computation is dead.

Eliminating unnecessary statements:
Deleting : *_4 ={v} {CLOBBER};

Deleting : _4 = &this_6(D)->data[_2];

IL before CDDCE:

  <bb 2> :
  _1 = this_6(D)->size;
  _2 = _1 + 18446744073709551615;
  this_6(D)->size = _2;
  _4 = &this_6(D)->data[_2];
  *_4 ={v} {CLOBBER};
  return;