ipa.c (symbol_table::remove_unreachable_nodes): Don't remove instumentation thunks calling reachable functions.

gcc/

	* ipa.c (symbol_table::remove_unreachable_nodes): Don't
	remove instumentation thunks calling reachable functions.
	* lto-cgraph.c (output_refs): Always output IPA_REF_CHKP.
	* lto/lto-partition.c (privatize_symbol_name_1): New.
	(privatize_symbol_name): Privatize both decl and orig_decl
	names for instrumented functions.
	* cgraph.c (cgraph_node::verify_node): Add transparent
	alias chain check for instrumented node.

gcc/testsuite/

	* gcc.dg/lto/chkp-privatize-1_0.c: New.
	* gcc.dg/lto/chkp-privatize-1_1.c: New.
	* gcc.dg/lto/chkp-privatize-2_0.c: New.
	* gcc.dg/lto/chkp-privatize-2_1.c: New.

From-SVN: r224063