News and compat annotation for #29316

(at-kwdef for parametric structs, and structs with supertypes).

Author: fredrikekre

NEWS.md

@@ -68,6 +68,7 @@ Standard library changes
   * `mul!`, `rmul!` and `lmul!` methods for `UniformScaling` ([#29506]).
   * `Symmetric` and `Hermitian` matrices now preserve the wrapper when scaled with a number ([#29469]).
   * New `edit(m::Module)` method which opens the main source file for module `m` ([#29636]).
+  * `Base.@kwdef` can now be used for parametric structs, and for structs with supertypes ([#29316]).
 
 Compiler/Runtime improvements
 -----------------------------

base/util.jl

@@ -651,6 +651,10 @@ Inner constructors can still be defined, but at least one should accept argument
 same form as the default inner constructor (i.e. one positional argument per field) in
 order to function correctly with the keyword outer constructor.
 
+!!! compat "Julia 1.1"
+    `Base.@kwdef` for parametric structs, and structs with supertypes
+    requires at least Julia 1.1.
+
 # Examples
 ```jldoctest
 julia> Base.@kwdef struct Foo