Add testcase for CREATE PROCEDURE with LANGUAGE clause

(cherry picked from commit b91485a)

Author: ZacJW

tests/sqlparser_common.rs

@@ -15411,3 +15411,33 @@ fn parse_create_procedure_with_parameter_modes() {
         _ => unreachable!(),
     }
 }
+
+#[test]
+fn parse_create_procedure_with_language() {
+    let sql = r#"CREATE PROCEDURE test_proc LANGUAGE sql AS BEGIN SELECT 1; END"#;
+    match verified_stmt(sql) {
+        Statement::CreateProcedure {
+            or_alter,
+            name,
+            params,
+            language,
+            ..
+        } => {
+            assert_eq!(or_alter, false);
+            assert_eq!(name.to_string(), "test_proc");
+            assert_eq!(params, Some(vec![]));
+            assert_eq!(
+                language,
+                Some(Ident {
+                    value: "sql".into(),
+                    quote_style: None,
+                    span: Span {
+                        start: Location::empty(),
+                        end: Location::empty()
+                    }
+                })
+            );
+        }
+        _ => unreachable!(),
+    }
+}