[Bug tree-optimization/77485] Missed dead store elimination of aggregate store followed by partial stores

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77485

--- Comment #7 from Jeffrey A. Law <law at redhat dot com> ---
There was a bit of cruft and a missed ADDR_EXPR in that last fragment of gimple
code.

;;   basic block 2, loop depth 0, count 0, freq 0, maybe hot
;;    prev block 0, next block 1, flags: (NEW, REACHABLE, VISITED)
;;    pred:       ENTRY (FALLTHRU,EXECUTABLE)
  __builtin_memset (&MEM[(struct FixBuf *)&<retval> + 31B], 0, 169);
  <retval>.buf[0] = 48;
  <retval>.buf[1] = 32;
[ ... ]
  return <retval>;