ipa: Do not modify cgraph edges from thunk clones during inlining (PR116572)

ipa: Do not modify cgraph edges from thunk clones during inlining (PR116572)

In PR 116572 we hit an assert that a thunk which does not have a body
looks like it has one.  It does not, but the call_stmt of its outgoing
edge points to a statement, which should not.  In fact it has several
outgoing call graph edges, which cannot be.  The problem is that the
code updating the edges to reflect inlining into the master clone (an
ex-thunk, unlike the clone, which is still an unexpanded thunk) is
being updated during inling into the master clone.  This patch simply
makes the code to skip unexpanded thunk clones.

gcc/ChangeLog:

2025-03-13  Martin Jambor  <mjambor@suse.cz>

	PR ipa/116572
	* cgraph.cc (cgraph_update_edges_for_call_stmt): Do not update
	edges of clones that are unexpanded thunk.  Assert that the node
	passed as the parameter is not an unexpanded thunk.

gcc/testsuite/ChangeLog:

2025-03-13  Martin Jambor  <mjambor@suse.cz>

	PR ipa/116572
	* g++.dg/ipa/pr116572.C: New test.

(cherry picked from commit 075ec330307c5b1fe5ed166a633c718c06b01437)