reflect: Value.Seq|Seq2 documentation and unexported value

[pierrre]

Go version

1.24

Output of go env in your module/workspace:

not relevant

What did you do?

Calling reflect.Value.Seq() panics if the value is unexported (CanInterface() returns false), but the documentation doesn't mention it.

What did you see happen?

It panics

What did you expect to see?

The documentation should explain that Seq() and Seq2() can be called if CanInterface() returns true, otherwise it panics.
I guess we should add the same warning to Call() and CallSlice()

[dmitshur]

CC @golang/runtime.