Interoperate with Base.@kwdef

[gafter]

@nystrom says in a comment on JuliaServices/AutoHashEqualsCached.jl#1:

Just FYI for when you process Base.@kwdef: fields in these structs can also be :(=) nodes with the field name and type in args[1] and the default value in args[2].

[gafter]

Also src/Compiler/Shared/auto-copy.jl in raicode

[gafter]

@kwdef also adds constructors that this package needs to be prepared to update.

[gafter]

This will allow raicode to eliminate this comment:

# @auto_hash_equals is incompatible with @kwdef, so we have to roll our hash and equality.

[jakobjpeters]

Would very much like this feature!