re PR lto/46879 (ICE: in separate_decls_in_region_debug_bind, at tree-parloops.c:778 with -flto -ftree-parallelize-loops -gdwarf-3)

	PR lto/46879
	* lto-streamer-out.c (output_gimple_stmt): Never replace first
	GIMPLE_DEBUG argument with MEM_REF.

From-SVN: r167755