ipa: Fix segmentation fault in function_summary<clone_info*>::get(cgraph_node*)

ipa: Fix segmentation fault in function_summary<clone_info*>::get(cgraph_node*)

PR 97660 occurs when cgraph_node::get returns NULL, and this NULL
cgraph_node is then passed to clone_info::get.  As the original assert
prior to the regressing change in r11-4587 allowed for the cgraph_node
to be NULL, clone_info::get is now only called when cgraph_node::get
returns a nonnull value.

gcc/ChangeLog:

	PR ipa/97660
	* cgraph.c (cgraph_edge::redirect_call_stmt_to_callee): Don't call
	clone_info::get when cgraph_node::get returns NULL.