Do not allocate ggc during streaming.

Do not allocate ggc during streaming.

	* gimple-streamer-out.c (output_gimple_stmt): Add explicit function
	parameter.
	* lto-streamer-out.c: Include tree-dfa.h.
	(output_cfg): Do not use cfun.
	(lto_prepare_function_for_streaming): New.
	(output_function): Do not push cfun; do not initialize loop optimizer.
	* lto-streamer.h (lto_prepare_function_for_streaming): Declare.
	* passes.c (ipa_write_summaries): Use it.
	(ipa_write_optimization_summaries): Do not modify bodies.
	* tree-dfa.c (renumber_gimple_stmt_uids): Add function parameter.
	* tree.dfa.h (renumber_gimple_stmt_uids): Update prototype.
	* tree-ssa-dse.c (pass_dse::execute): Update use of
	renumber_gimple_stmt_uids.
	* tree-ssa-math-opts.c (pass_optimize_widening_mul::execute): Likewise.

	* lto.c (lto_wpa_write_files): Prepare all bodies for streaming.

From-SVN: r276870