discriminators: Fix assigning discriminators on edge [PR113546]

discriminators: Fix assigning discriminators on edge [PR113546]

The problem here is there was a compare debug since the discriminators
would still take into account debug statements. For the edge we would look
at the first statement after the labels and that might have been a debug statement.
So we need to skip over debug statements otherwise we could get different
discriminators # with and without -g.

Bootstrapped and tested on x86_64-linux-gnu with no regressions.

	PR middle-end/113546

gcc/ChangeLog:

	* tree-cfg.cc (first_non_label_stmt): Rename to ...
	(first_non_label_nondebug_stmt): This and use gsi_start_nondebug_after_labels_bb.
	(assign_discriminators): Update call to first_non_label_nondebug_stmt.

gcc/testsuite/ChangeLog:

	* c-c++-common/torture/pr113546-1.c: New test.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>