libsigsegv: fix sparc64 compile

Compile tested for sparc/glibc and sparc64/glibc.
Fixes following autobuilder problem:
http://autobuild.buildroot.net/results/1d8e0c22594aef53f7a4de3491454aa78311c815/

Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libsigsegv/0005-fix-sparc64-stackpointer.patch

@@ -0,0 +1,16 @@
+Fix sparc64 build.
+
+Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
+
+diff -Nur libsigsegv-2.10.orig/src/fault-linux-sparc.h libsigsegv-2.10/src/fault-linux-sparc.h
+--- libsigsegv-2.10.orig/src/fault-linux-sparc.h	2009-08-01 17:06:49.000000000 +0200
++++ libsigsegv-2.10/src/fault-linux-sparc.h	2015-11-29 11:55:29.000000000 +0100
+@@ -27,4 +27,8 @@
+    (see also <asm/sigcontext.h>)
+    are quite different types.  */
+ 
++#if __WORDSIZE == 64
++#define SIGSEGV_FAULT_STACKPOINTER  ((ucontext_t *) ucp)->uc_mcontext.mc_gregs[REG_O6]
++#else
+ #define SIGSEGV_FAULT_STACKPOINTER  ((ucontext_t *) ucp)->uc_mcontext.gregs[REG_O6]
++#endif