* To extend nmigen "Type 1 (ast.*)" low-level language constructs
in the Value class
with `Value.__Cat__`, `Value.__Switch__`, `Value.__Repl__` etc.
-* To rename existing old `ast.Cat` to new `ast._InternalCat`,
- `ast.Repl` to `ast._InternalRepl` etc.
+* To rename existing old
+ - `ast.Cat` to new `ast._InternalCat`,
+ - `ast.Repl` to `ast._InternalRepl`
+ - etc.
* In an identical conceptual fashion, just
as python `operator.add(x,y)` redirects to `x.__add__(y)`,
to add a new `ast.Cat(x..)` which redirects to`x.__Cat__(...)` etc.