Restore stashed tokenizer.rs changes (tokenize_lt test)

Applied stashed changes from before the merge: adds a tokenize_lt test
case for 'SELECT a < -5' with geometric types dialects. Merged into
the upstream's existing tokenize_lt function to avoid duplication.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ayman-sigma

src/tokenizer.rs

@@ -4613,5 +4613,18 @@ mod tests {
                 Token::make_word("b", None),
             ],
         );
+        all_dialects_where(|d| d.supports_geometric_types()).tokenizes_to(
+            "SELECT a < -5",
+            vec![
+                Token::make_keyword("SELECT"),
+                Token::Whitespace(Whitespace::Space),
+                Token::make_word("a", None),
+                Token::Whitespace(Whitespace::Space),
+                Token::Lt,
+                Token::Whitespace(Whitespace::Space),
+                Token::Minus,
+                Token::Number("5".to_string(), false),
+            ],
+        );
     }
 }