[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 #1 from Ian Lance Taylor <ian at airs dot com> ---
Would it be possible for you to check whether the patch at
https://golang.org/cl/52611 fixes the problem?

Actually I'll attach it here.