Fix Solaris build.

From Rainer Orth.

From-SVN: r180439

libgo/go/syscall/wait.c

@@ -95,7 +95,7 @@ extern int TrapCause (uint32_t *w)
   __asm__ ("libgo_syscall.syscall.TrapCause.N32_libgo_syscall.syscall.WaitStatus");
 
 int
-TrapCause (uint32_t *w)
+TrapCause (uint32_t *w __attribute__ ((unused)))
 {
 #ifndef __linux__
   return -1;

libgo/mksysinfo.sh

@@ -251,7 +251,7 @@ if ! grep '^const PTRACE_EVENT_EXIT' ${OUT} > /dev/null 2>&1; then
   echo "const PTRACE_EVENT_EXIT = 6" >> ${OUT}
 fi
 if ! grep '^const _PTRACE_TRACEME' ${OUT} > /dev/null 2>&1; then
-  echo "const PTRACE_TRACEME = 0" >> ${OUT}
+  echo "const _PTRACE_TRACEME = 0" >> ${OUT}
 fi
 
 # The registers returned by PTRACE_GETREGS.  This is probably