cl-typeck: Crate-spanning refactor part 2

- Removed all unreferenced files
- Reimplemented missing/nonfunctional behavior
- Added module documentation for most things
  - TODO: item-level docs on Entry(Mut)
- Reparented the stages of Table population into the `stage` module.
  - TODO: rewrite type inference to use only the tools provided by Table.

stdlib/test.cl

@@ -27,7 +27,7 @@ enum Hodgepodge {
 
 fn noop () -> bool {
     loop if false {
-        
+
     } else break loop if false {
         
     } else break loop if false {
@@ -62,3 +62,18 @@ fn if_else() -> i32 {
     }
     // block 4
 }
+
+mod horrible_imports {
+    mod foo {
+        use super::{bar::*, baz::*};
+        struct Foo(&Foo, &Bar)
+    }
+    mod bar {
+        use super::{foo::*, baz::*};
+        struct Bar(&Foo, &Baz)
+    }
+    mod baz {
+        use super::{foo::*, bar::*};
+        struct Baz(&Foo, &Bar)
+    }
+}