Fix linux-unwind.h gcc-mirror#2.

Author: marxin

gcc/config/i386/linux-unwind.h

@@ -137,9 +137,9 @@ x86_fallback_frame_state (struct _Unwind_Context *context,
     {
       struct rt_sigframe {
 	int sig;
-	struct siginfo *pinfo;
+	siginfo_t *pinfo;
 	void *puc;
-	struct siginfo info;
+	siginfo_t info;
 	ucontext_t uc;
       } *rt_ = context->cfa;
       /* The void * cast is necessary to avoid an aliasing warning.