RISC-V: Moved syscalls to separate files to fix aliasing problems.

libgloss/riscv/sys_kill.c

@@ -0,0 +1,11 @@
+#include <machine/syscall.h>
+#include "internal_syscall.h"
+
+/* Send a signal. Minimal implementation for a system without processes
+   just causes an error.  */
+int
+_kill(int pid, int sig)
+{
+  errno = EINVAL;
+  return -1;
+}