ALT Linux Bugzilla – #12117

When trying to open very large files (but not devices), gpart stops with "File 
too large" error messages.

replacing O_RDONLY with O_RDONLY|O_LARGEFILE and adding  -D_LARGEFILE64_SOURCE 
to the compile options seems to help.

So I'm attaching a patch, hoping it's useful.
Steps to Reproduce:
1. # dd if=/dev/sda of=somefile
    /dev/sda size >= several gig
2. # gpart -g somefile 

Actual Results:  
fails to open

Expected Results:  
gpart should work as if it was operating on a drive