[Bug go/81617] mksigtab.sh fails to resolve NSIG with glibc 2.26

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81617

--- Comment #2 from Ian Lance Taylor <ian at airs dot com> ---
Created attachment 41900
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41900&action=edit
possible patch