crypto/x509: NameConstraintsWithoutSANs when checking signing certificate [1.10 backport]

[gopherbot]

@FiloSottile requested issue #24151 to be considered for backport to the next 1.10 minor release.

@gopherbot please open a 1.10.2 backport tracking issue, as this is a regression.

(I am developing this gopherbot feature now, so don't expect to see it work right away. The new process is documented at https://github.com/golang/go/wiki/MinorReleases and will be announced when gopherbot works.)

[FiloSottile]

See the main issue for some existing discussion of what, if anything, should go in the minor release.

[andybons]

Moving to 1.10.3 as there doesn't seem to be consensus on what to include.

[FiloSottile]

See #24151 (comment).