lra: Ignore debug insns and notes in combine_reload_insn [PR109179]

We ICE in combine_reload_insn if we've deleted the TO insn operand during
processing, because lra_get_insn_recog_data doesn't expect to see the note
that replaces the deleted insn.  The solution here is to exit early if TO
is a debug insn or note.

2023-03-17  Peter Bergner  <bergner@linux.ibm.com>

gcc/
	PR rtl-optimization/109179
	* lra-constraints.cc (combine_reload_insn): Enforce TO is not a debug
	insn or note.  Move the tests earlier to guard lra_get_insn_recog_data.