Propose a change in open for passing in the file type.

Hi Everyone,
 
Am working on porting git to z/OS. For reference, the pull request am working on https://github.com/git/git/pull/1537.
 
On z/OS there is a notion of file tag attributes. Files can be tagged as binary, ASCII, UTF8, EBCDIC, etc. z/OS uses these attributes to determine if auto-conversion is necessary. It was recommended in PR that we add logic directly to xopen . In order for me to do this in xopen , I have to pass an extra parameter to xopen that specifies the file type. 
 
Ex: 
xopen(output_file, O_CREAT | O_WRONLY | O_TRUNC, 0666);
 
To :
xopen(output_file, O_CREAT | O_WRONLY | O_TRUNC, 0666, BINARY);
 
BINARY: would be an enum value.
 
Would this be okay to do? Or are there other recommendations?
 
Best regards
Haritha