targhooks.c (default_hidden_stack_protect_fail): Fall back to default_external_stack_...

targhooks.c (default_hidden_stack_protect_fail): Fall back to default_external_stack_protect_fail if...

	* targhooks.c (default_hidden_stack_protect_fail): Fall back to
	default_external_stack_protect_fail if visibility is not supported
	or not flag_pic.
	* config/i386/i386.c (ix86_stack_protect_fail): New function.
	(TARGET_STACK_PROTECT_FAIL): Define.
	* config/i386/i386.md (stack_protect_si): Change CLOBBER into
	SET to zero.
	(stack_protect_di): Likewise.  Use %k2 instead of %2 to avoid
	invalid instruction xorl %rax, %rax.

From-SVN: r101349