Fix compile with GCC 5 -Werror
newlib/libc/
* stdio64/freopen64.c: Include <string.h> for memset().
* stdlib/quick_exit.c: Include <unistd.h> for _exit().
* string/gnu_basename.c (__gnu_basename): Fix discarded const
qualifier warning.
* stdlib/strtold.c: Include "mprec.h" for _strtorx_r().
Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>