Fix var tracking ICE due to reorg.

Fix var tracking ICE due to reorg.

If during reorg we delete a code label, and as a result we decide to
delete all the code following that label, we hit this condition in
jump.c:delete_related_insns():

  if (was_code_label && prev && BARRIER_P (prev))

which passes and then we proceed to delete insns until we hit a
non-deleted code label.

During this traversal, we can end up deleting a CALL, but in doing so
we will leave the var tracking note for the call arguments around.

Later in dwarf2_var_location() we will ICE, because we can't find the
CALL when we search backwards for it.

The note searching scheme in the fix below is cribbed from code in
try_split() which has to handle a similar problem.

gcc/

	* jump.c (delete_related_insns): If we remove a CALL, make sure
	we delete it's NOTE_INSN_CALL_ARG_LOCATION note too.

From-SVN: r187606