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

libgloss/riscv/sys_wait.c

@@ -0,0 +1,10 @@
+#include <machine/syscall.h>
+#include <errno.h>
+
+/* Wait for a child process. Minimal implementation for a system without
+   processes just causes an error.  */
+int _wait(int *status)
+{
+  errno = ECHILD;
+  return -1;
+}