PartitionedSignal, which in turn provides "Type 1 (ast.*)" nmigen language
constructs in the form described above.
+* [[dynamic_simd/shape]] a derivative of ast.Shape with partition info
* [[dynamic_simd/assign]] nmigen eq (ast.Assign)
* [[dynamic_simd/cat]] nmigen ast.Cat
* [[dynamic_simd/repl]] nmigen ast.Repl