parser: Parse char immediates into Expr::Number

src/parser.rs

@@ -173,6 +173,10 @@ impl<'t> Parser<'t> {
                 self.take();
                 Expr::Number(n)
             }
+            Kind::Char(c) => {
+                self.take();
+                Expr::Number(c as _)
+            }
             Kind::Identifier => {
                 self.take();
                 Expr::Ident(lexeme)