cl-typeck: More type inference

- Renamed "intrinsic" -> "primitive"
  - I thought it was funny, but it's just annoying.
- Rename "Uninferred" -> "Inferred"
  - It's a concrete type, but an inferred one.
- Add lifetimes to the Entry API
- Categorize does not care about recursive types. You can't have a recursive AST.
- Added helpful constructors to the inference engine
- Added some overloadable operators to the inference engine
  - These are a MAJOR work in progress
- Reorganized the Inference implementation file by functionality.

stdlib:
- Updated standard library.

compiler/cl-ast/src/ast_impl/path.rs

@@ -21,9 +21,10 @@ impl Path {
         }
     }
 
+    /// Gets the defining [Sym] of this path
     pub fn as_sym(&self) -> Option<Sym> {
         match self.parts.as_slice() {
-            [PathPart::Ident(name)] => Some(*name),
+            [.., PathPart::Ident(name)] => Some(*name),
             _ => None,
         }
     }