[Bug tree-optimization/107775] missed optimization in vec_set lower part of vector in the memory.

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107775

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
  MEM[(v2df *)&v] = reg.0_1;
  v[0] = b_5(D);
  _2 = MEM[(v2df *)&v];

Maybe that could be converted into:
  MEM[(v2df *)&v] = reg.0_1;
  BIT_FIELD_REF <v, 64, 0> = b_2(D);
  _2 = MEM[(v2df *)&v];


BIT_INSERT_EXPR ...