chore: sort arithmetic tokens alphabetically

Author: ge28boj

mlir/lib/Tools/PDLL/Parser/Lexer.h

@@ -80,15 +80,18 @@ class Token {
     equal,
     equal_arrow,
     semicolon,
-    /// Paired punctuation.
+
+    /// Arithmetic.
+    abs,
     add,
-    sub,
-    mul,
     div,
-    mod,
-    log2,
     exp2,
-    abs,
+    log2,
+    mod,
+    mul,
+    sub,
+
+    /// Paired punctuation.
     less,
     greater,
     l_brace,