PR target/77957
	* hooks.h (hook_tree_void_null): Declare.
	* hooks.c (hook_tree_void_null): New function.
	* langhooks.c (lhd_return_null_tree_v): Remove.
	* langhooks-def.h (lhd_return_null_tree_v): Remove.
	* cfgexpand.c (stack_protect_prologue): If guard_decl is NULL,
	set y to const0_rtx.
	* function.c (stack_protect_epilogue): Likewise.
	* config/tilepro/tilepro.c (TARGET_STACK_PROTECT_GUARD): Redefine
	if TARGET_THREAD_SSP_OFFSET is defined.
	* config/s390/s390.c (TARGET_STACK_PROTECT_GUARD): Likewise.
	* config/sparc/sparc.c (TARGET_STACK_PROTECT_GUARD): Likewise.
	* config/tilegx/tilegx.c (TARGET_STACK_PROTECT_GUARD): Likewise.
	* config/rs6000/rs6000.c (TARGET_STACK_PROTECT_GUARD): Likewise.
	* config/i386/i386.c (TARGET_STACK_PROTECT_GUARD): Likewise.
	(ix86_stack_protect_guard): New function.
c/
	* c-objc-common.h (LANG_HOOKS_GETDECLS): Use hook_tree_void_null
	instead of lhd_return_null_tree_v.
ada/
	* gcc-interface/misc.c (LANG_HOOKS_GETDECLS): Use hook_tree_void_null
	instead of lhd_return_null_tree_v.

From-SVN: r241087