refactor and split test_linearizer (#12001)

* refactor and split test_linearizer

* forget that file

* imports

* remove from docs

* test gen float4

docs/developer/layout.md

@@ -22,12 +22,6 @@ Group UOps into kernels.
 
 Transforms the ast into an optimized ast. This is where BEAM search and heuristics live.
 
-::: tinygrad.codegen.opt.get_optimized_ast
-    options:
-        members: false
-        show_labels: false
-        show_source: false
-
 ---
 
 ## tinygrad/codegen