re PR c++/59813 (tail-call elimination didn't fire for left-shift of char to cout)

	PR c++/59813
	PR target/90418
	* function.h (struct function): Add calls_eh_return member.
	* gimplify.c (gimplify_call_expr): Set cfun->calls_eh_return when
	gimplifying __builtin_eh_return call.
	* tree-inline.c (initialize_cfun): Copy calls_eh_return from src_cfun
	to cfun.
	(expand_call_inline): Or in src_cfun->calls_eh_return into
	dst_cfun->calls_eh_return.
	* tree-tailcall.c (suitable_for_tail_call_opt_p): Return false if
	cfun->calls_eh_return.
	* lto-streamer-in.c (input_struct_function_base): Read calls_eh_return.
	* lto-streamer-out.c (output_struct_function_base): Write
	calls_eh_return.

From-SVN: r271440