encoding/binary: fix NativeEndian == BigEndian || NativeEndian == LittleEndian about go

[seankhliao]

As they are different types, equality isn't possible (nor is it generally expected of unexported types).

[dolmen]

@seankhliao My point is that they should not be different types, but instead defined using a type alias. For this reason I'm asking this issue to be reopened.

Cc: @tklauser #57237 (comment)

[gopherbot]

Change https://go.dev/cl/581655 mentions this issue: encoding/binary: fix NativeEndian to support == with Little/BigEndian

[dolmen]

@seankhliao Please review CL581655 which fixes this issue.

[dolmen]

Cc: @randall77 because #57237 (comment)

[dolmen]

I realize that my TestEqual in the description is flawed: the bo is of type binary.ByteOrder (an interface) so the comparaison happens at runtime.

However for binary.NativeEndian == binary.BigEndian, the type are resolved at compile time and a mismatch is detected like with binary.LittleEndian == binary.BigEndian:

invalid operation: binary.LittleEndian == binary.BigEndian (mismatched types binary.littleEndian and binary.bigEndian)

So this issue deserved to be closed.