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

libgloss/riscv/sys_lseek.c

@@ -0,0 +1,10 @@
+#include <machine/syscall.h>
+#include <sys/types.h>
+#include "internal_syscall.h"
+
+/* Set position in a file.  */
+off_t
+_lseek(int file, off_t ptr, int dir)
+{
+  return syscall_errno (SYS_lseek, file, ptr, dir, 0, 0, 0);
+}