PR go/78172.
    libgo: avoid confusion in upcase_fields in mksysinfo.sh
    
    The mksysinfo.sh script could get confused when there were multiple
    types starting with the same name.  I believe this is the underlying
    cause of GCC PR 78172.
    
    Also redirect a grep to /dev/null to avoid extraneous messages during
    the build.
    
    Reviewed-on: https://go-review.googlesource.com/32821

From-SVN: r241868