[bug-gnu-libiconv] GNU LIBICONV cannot run check on MinGW.

[1 1]

Hi there

When I run 'make check' for GNU LIBICONV on MinGW-w64. It reported an error 
like this:
```
./ASCII.TXT tmp-ASCII.TXT differ: byte 12, line 1
make[1]: *** [Makefile:32: check] Error 1
```
I think this may be caused by CR lF.
I think we need to solve it, after all, MinGW is a GNU environment, which 
cannot verify whether it is a bug in GNU LIBICONV or a problem caused by CR LF

Thanks.