conlang: Remove "self" keyword

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

@@ -4,7 +4,6 @@ use super::*;
 impl<T: AsRef<str>> From<T> for PathPart {
     fn from(value: T) -> Self {
         match value.as_ref() {
-            "self" => PathPart::SelfKw,
             "super" => PathPart::SuperKw,
             ident => PathPart::Ident(ident.into()),
         }

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

@@ -370,7 +370,6 @@ impl Display for PathPart {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             PathPart::SuperKw => "super".fmt(f),
-            PathPart::SelfKw => "self".fmt(f),
             PathPart::SelfTy => "Self".fmt(f),
             PathPart::Ident(id) => id.fmt(f),
         }

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

@@ -264,7 +264,6 @@ impl WeightOf for PathPart {
     fn weight_of(&self) -> usize {
         match self {
             PathPart::SuperKw => size_of_val(self),
-            PathPart::SelfKw => size_of_val(self),
             PathPart::SelfTy => size_of_val(self),
             PathPart::Ident(interned) => interned.weight_of(),
         }