There is one usage in boehm-gc/os_dep.c, but it is only used if
SUNOS5SIGS is defined, which it is only if one of SUNOS5, DRSNX, HPUX, or
FREEBSD is defined, which are all not using Linux-based glibc ports.

Likewise, gcc/ada/init.c has a struct __siginfo occurence, but only for
__FreeBSD__.

config/rs6000/linux-unwind.h uses ``char siginfo[128]'', and
config/s390/linux-unwind.h also uses a constant.

I tested the following patch for sh-linux-gnu.  This only covers one
configuration, but the change is pretty mechanic anyway and every place
that used to refer to struct siginfo already must have had <signal.h> in
its include path, which is the same file that declares siginfo_t.

OK to commit?  This should probably also go into any active release
branches, to keep them buildable once this glibc change ripples through?

gcc/
        * config/alpha/linux-unwind.h (alpha_fallback_frame_state): Use
        siginfo_t instead of struct siginfo.
        * config/bfin/linux-unwind.h (bfin_fallback_frame_state): Likewise.
        * config/i386/linux-unwind.h (x86_fallback_frame_state): Likewise.
        * config/ia64/linux-unwind.h (ia64_fallback_frame_state)
        (ia64_handle_unwabi): Likewise.
        * config/mips/linux-unwind.h (mips_fallback_frame_state): Likewise.
        * config/pa/linux-unwind.h (pa32_fallback_frame_state): Likewise.
        * config/sh/linux-unwind.h (shmedia_fallback_frame_state)
        (sh_fallback_frame_state): Likewise.
        * config/tilepro/linux-unwind.h (tile_fallback_frame_state): Likewise.
        * config/xtensa/linux-unwind.h (xtensa_fallback_frame_state): Likewise.

---
diff -urN gcc-linaro-4.6-2012.02/gcc/config/alpha/linux-unwind.h gcc-linaro-4.6-2012.02.new/gcc/config/alpha/linux-unwind.h
--- gcc-linaro-4.6-2012.02/gcc/config/alpha/linux-unwind.h	2012-02-07 11:33:31.000000000 +0100
+++ gcc-linaro-4.6-2012.02.new/gcc/config/alpha/linux-unwind.h	2012-09-13 10:25:52.919072751 +0200
@@ -49,7 +49,7 @@
   else if (pc[1] == 0x201f015f)		/* lda $0,NR_rt_sigreturn */
     {
       struct rt_sigframe {
-	struct siginfo info;
+	siginfo_t info;
 	struct ucontext uc;
       } *rt_ = context->cfa;
       sc = &rt_->uc.uc_mcontext;
diff -urN gcc-linaro-4.6-2012.02/gcc/config/bfin/linux-unwind.h gcc-linaro-4.6-2012.02.new/gcc/config/bfin/linux-unwind.h
--- gcc-linaro-4.6-2012.02/gcc/config/bfin/linux-unwind.h	2012-02-07 11:33:31.000000000 +0100
+++ gcc-linaro-4.6-2012.02.new/gcc/config/bfin/linux-unwind.h	2012-09-13 10:26:14.819073313 +0200
@@ -48,10 +48,10 @@
     {
       struct rt_sigframe {
 	int sig;
-	struct siginfo *pinfo;
+	siginfo_t *pinfo;
 	void *puc;
 	char retcode[8];
-	struct siginfo info;
+	siginfo_t info;
 	struct ucontext uc;
       } *rt_ = context->cfa;
 
diff -urN gcc-linaro-4.6-2012.02/gcc/config/i386/linux-unwind.h gcc-linaro-4.6-2012.02.new/gcc/config/i386/linux-unwind.h
--- gcc-linaro-4.6-2012.02/gcc/config/i386/linux-unwind.h	2012-02-07 11:33:31.000000000 +0100
+++ gcc-linaro-4.6-2012.02.new/gcc/config/i386/linux-unwind.h	2012-09-13 10:26:41.891074005 +0200
@@ -133,9 +133,9 @@
     {
       struct rt_sigframe {
 	int sig;
-	struct siginfo *pinfo;
+	siginfo_t *pinfo;
 	void *puc;
-	struct siginfo info;
+	siginfo_t info;
 	struct ucontext uc;
       } *rt_ = context->cfa;
       /* The void * cast is necessary to avoid an aliasing warning.
diff -urN gcc-linaro-4.6-2012.02/gcc/config/ia64/linux-unwind.h gcc-linaro-4.6-2012.02.new/gcc/config/ia64/linux-unwind.h
--- gcc-linaro-4.6-2012.02/gcc/config/ia64/linux-unwind.h	2012-02-07 11:33:31.000000000 +0100
+++ gcc-linaro-4.6-2012.02.new/gcc/config/ia64/linux-unwind.h	2012-09-13 10:26:59.251074450 +0200
@@ -47,7 +47,7 @@
       struct sigframe {
 	char scratch[16];
 	unsigned long sig_number;
-	struct siginfo *info;
+	siginfo_t *info;
 	struct sigcontext *sc;
       } *frame_ = (struct sigframe *)context->psp;
       struct sigcontext *sc = frame_->sc;
@@ -137,7 +137,7 @@
       struct sigframe {
 	char scratch[16];
 	unsigned long sig_number;
-	struct siginfo *info;
+	siginfo_t *info;
 	struct sigcontext *sc;
       } *frame = (struct sigframe *)context->psp;
       struct sigcontext *sc = frame->sc;
diff -urN gcc-linaro-4.6-2012.02/gcc/config/mips/linux-unwind.h gcc-linaro-4.6-2012.02.new/gcc/config/mips/linux-unwind.h
--- gcc-linaro-4.6-2012.02/gcc/config/mips/linux-unwind.h	2012-02-07 11:33:31.000000000 +0100
+++ gcc-linaro-4.6-2012.02.new/gcc/config/mips/linux-unwind.h	2012-09-13 10:27:17.947074929 +0200
@@ -75,7 +75,7 @@
       struct rt_sigframe {
 	u_int32_t ass[4];  /* Argument save space for o32.  */
 	u_int32_t trampoline[2];
-	struct siginfo info;
+	siginfo_t info;
 	_sig_ucontext_t uc;
       } *rt_ = context->cfa;
       sc = &rt_->uc.uc_mcontext;
diff -urN gcc-linaro-4.6-2012.02/gcc/config/pa/linux-unwind.h gcc-linaro-4.6-2012.02.new/gcc/config/pa/linux-unwind.h
--- gcc-linaro-4.6-2012.02/gcc/config/pa/linux-unwind.h	2012-02-07 11:33:31.000000000 +0100
+++ gcc-linaro-4.6-2012.02.new/gcc/config/pa/linux-unwind.h	2012-09-13 10:27:27.491075173 +0200
@@ -63,7 +63,7 @@
   int i;
   struct sigcontext *sc;
   struct rt_sigframe {
-    struct siginfo info;
+    siginfo_t info;
     struct ucontext uc;
   } *frame;
 
diff -urN gcc-linaro-4.6-2012.02/gcc/config/sh/linux-unwind.h gcc-linaro-4.6-2012.02.new/gcc/config/sh/linux-unwind.h
--- gcc-linaro-4.6-2012.02/gcc/config/sh/linux-unwind.h	2012-02-07 11:33:31.000000000 +0100
+++ gcc-linaro-4.6-2012.02.new/gcc/config/sh/linux-unwind.h	2012-09-13 10:27:58.551075969 +0200
@@ -80,9 +80,9 @@
 	   && (*(unsigned long *) (pc+11)  == 0x6ff0fff0))
     {
       struct rt_sigframe {
-	struct siginfo *pinfo;
+	siginfo_t *pinfo;
 	void *puc;
-	struct siginfo info;
+	siginfo_t info;
 	struct ucontext uc;
       } *rt_ = context->cfa;
       /* The void * cast is necessary to avoid an aliasing warning.
@@ -179,7 +179,7 @@
 		&& (*(unsigned short *) (pc+14)  == 0x00ad))))
     {
       struct rt_sigframe {
-	struct siginfo info;
+	siginfo_t info;
 	struct ucontext uc;
       } *rt_ = context->cfa;
       /* The void * cast is necessary to avoid an aliasing warning.
diff -urN gcc-linaro-4.6-2012.02/gcc/config/xtensa/linux-unwind.h gcc-linaro-4.6-2012.02.new/gcc/config/xtensa/linux-unwind.h
--- gcc-linaro-4.6-2012.02/gcc/config/xtensa/linux-unwind.h	2012-02-07 11:33:31.000000000 +0100
+++ gcc-linaro-4.6-2012.02.new/gcc/config/xtensa/linux-unwind.h	2012-09-13 10:28:13.827076359 +0200
@@ -62,7 +62,7 @@
   struct sigcontext *sc;
 
   struct rt_sigframe {
-    struct siginfo info;
+    siginfo_t info;
     struct ucontext uc;
   } *rt_;