[Bug c++/90307] -Wuninitialized only at -O1, not at -O2

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90307

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
SRA decided to do this:
  [t88.c:27:24] x.u.internal = [t88.c:27:30] [t88.c:27:28] MEM[(const struct
sstring &)[t88.c:49:17] &s].u.internal;
  [t88.c:27:24] x$u$external$str_24 = [t88.c:27:24] MEM[(union contents *)&s];
  [t88.c:27:24] x$u$external$size_64 = [t88.c:27:24] MEM[(union contents *)&s +
8B];
  [t88.c:25:31] MEM[(struct  &)[t88.c:51:12] &D.2505] ={v} {CLOBBER};
  [t88.c:27:24] [t88.c:27:24] MEM[(union contents *)&x] = x$u$external$str_24;
  [t88.c:27:24] [t88.c:27:24] MEM[(union contents *)&x + 8B] =
x$u$external$size_64;
  [t88.c:27:24] [t88.c:27:24] MEM[(union contents *)&x + 15B] = 5;