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