[Bug rtl-optimization/82683] Combine: GCC generates bad code with -tune=thunderx2t99

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82683

--- Comment #10 from Segher Boessenkool <segher at gcc dot gnu.org> ---
reg-notes.def says

/* The value in REG dies in this insn (i.e., it is not needed past
   this insn).  If REG is set in this insn, the REG_DEAD note may,
   but need not, be omitted.  */
REG_NOTE (DEAD)

so the notes should have gone to insn 20 here, not insn 21 (which
is a new r83).  Or deleted altogether.