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>

newlib/libc/stdio64/freopen64.c

@@ -74,6 +74,7 @@ Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
 
 #include <time.h>
 #include <stdio.h>
+#include <string.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdlib.h>