[Bug target/79570] [5/6/7 Regression] ICE in sel-sched-ir.c:4534 in pr69956.c

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79570

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Seems before r197942 sel_remove_insn with only_disconnect true actually kept
BLOCK_FOR_INSN on the (temporarily) removed insn. But sel_bb_head would
certainly not return that temporarily removed insn, so what the patch does
preserves what we used to do before in that case.