[patch, testsuite] skip broken test on Windows

[Sandra Loosemore]

On 09/25/2018 10:58 AM, Nick Clifton wrote:
> Hi Sandra,
> 
>> This patch is a followup to PR23153, in which it was reported that gas's inode comparison test for identical input and output files doesn't work on MinGW hosts,
> 
> Is this still the case ?  We did make some improvements to the code
> (So that it also checks the st_dev field, and if the inode is 0,
> then the check is assumed to have failed).

It does not diagnose the error if both input and output files have inode 
0 (which is what happens on mingw host).  So, instead of producing the 
expected error, the testcase proceeds to overwrite its input file.  This 
is bad.  :-(

-Sandra