combine: Fix PR80233
If combine has added an unconditional trap there will be a new basic
block as well. It will then end up considering the NOTE_INSN_BASIC_BLOCK
as the last_combined_insn, but then it tries to take the DF_INSN_LUID
of that and that dereferences a NULL pointer (since such a note is not
an INSN_P).
This fixes it by not taking non-insns as last_combined_insn.
PR rtl-optimization/80233
* combine.c (combine_instructions): Only take NONDEBUG_INSN_P insns
as last_combined_insn. Do not test for BARRIER_P separately.
gcc/testsuite/
PR rtl-optimization/80233
* gcc.c-torture/compile/pr80233.c: New testcase.
From-SVN: r246575