drop attempt to reuse cgraph callees for -fcallgraph-info

drop attempt to reuse cgraph callees for -fcallgraph-info

The information in cgraph callees is released long before we get to
the point in which -fcallgraph-info edges are dumped, or even
expanded.  It doesn't make sense to retain it longer: the edges
created for -fcallgraph-info are much smaller, and they don't even
coexist, so not even peak use grows.

for  gcc/ChangeLog

	* function.h (CALLEE_FROM_CGRAPH_P): Remove.
	* function.c (record_final_call): Record even calls that might
	have been in the cgraph.
	* toplev.c (dump_final_node_vcg): Skip iteration over cgraph
	callees.

From-SVN: r278529