Add file-driven test cases for the clause-level MySQL 26.7 sweep

[kyleconroy]

Summary

The first coverage sweep (#38) probed the MySQL 26.7 reference manual at statement-family granularity (Chapter 15, SQL Statements), which #39–#42 then implemented. This PR is the second sweep at the next level of granularity: each Chapter 15 statement's full syntax diagram (every optional clause), Chapter 14 function-specific syntax, Chapter 11 lexical features, Chapter 13 type and column-attribute grammar, Chapter 10 §10.9 optimizer hints, and Chapter 26 partitioning.

Roughly 930 documented statements were probed against the parser. The 148 that fail to parse are recorded as error goldens in twelve new testdata/parser groups, following the #38 convention: when a statement gains support, its -- error segment turns into a Restore() golden and the diff makes the coverage change explicit.

New test groups

Group	Gaps documented
mysql_unsupported_types	INVISIBLE/VISIBLE column attribute (incl. the GIPK SHOW CREATE TABLE round-trip and ALTER ... SET VISIBLE), column-level ENGINE_ATTRIBUTE, DEFAULT (expr) with operators (only bare function calls parse today)
mysql_unsupported_functions	JSON_TABLE, JSON_VALUE RETURNING/ON EMPTY/ON ERROR, CAST ... AT TIME ZONE, CAST AS NCHAR, SOUNDS LIKE
mysql_unsupported_routines	every CREATE PROCEDURE characteristic (COMMENT, LANGUAGE SQL, DETERMINISTIC, CONTAINS/NO SQL, READS/MODIFIES SQL DATA, SQL SECURITY), LANGUAGE JAVASCRIPT bodies with dollar-quoted strings, CREATE LIBRARY $$-bodies and the USING clause
mysql_unsupported_account	IDENTIFIED BY RANDOM PASSWORD, multi-factor auth (AND IDENTIFIED, ADD/MODIFY/DROP n FACTOR, registration flow), dual-password clauses (REPLACE/RETAIN CURRENT PASSWORD/DISCARD OLD PASSWORD), DEFAULT ROLE on CREATE/ALTER USER, PASSWORD REQUIRE CURRENT, GRANT ... AS user WITH ROLE, GRANT role WITH ADMIN OPTION, REVOKE IF EXISTS/IGNORE UNKNOWN USER, REVOKE PROXY, SET PASSWORD TO RANDOM
mysql_unsupported_admin	histogram USING DATA and AUTO/MANUAL UPDATE, INSTALL COMPONENT SET PERSIST, DROP RESOURCE GROUP FORCE, SET RESOURCE GROUP ... FOR, FLUSH OPTIMIZER_COSTS/RELAY LOGS/USER_RESOURCES/TABLES FOR EXPORT/multi-option lists, SET PERSIST/PERSIST_ONLY
mysql_unsupported_show	SHOW STORAGE ENGINES, SHOW WARNINGS/ERRORS LIMIT, SHOW EXTENDED INDEX, SHOW REPLICA STATUS FOR CHANNEL
mysql_unsupported_ddl	AUTOEXTEND_SIZE, CREATE TABLE ... START TRANSACTION, CREATE INDEX ENGINE_ATTRIBUTE, ALTER DATABASE READ ONLY, WITH CHECK OPTION without a CASCADED/LOCAL qualifier
mysql_unsupported_dml	INTO OUTFILE ... CHARACTER SET, multiple locking clauses, INTO before a locking clause, derived-table column lists, LOAD DATA CONCURRENT/PARTITION/IGNORE n ROWS
mysql_unsupported_txn	BEGIN/COMMIT/ROLLBACK WORK, START TRANSACTION characteristic lists, LOCK TABLES aliases and LOW_PRIORITY WRITE
mysql_unsupported_replication	CHANGE REPLICATION SOURCE options with non-literal values (IGNORE_SERVER_IDS, PRIVILEGE_CHECKS_USER, REQUIRE_TABLE_PRIMARY_KEY_CHECK, ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS), RESET BINARY LOGS AND GTIDS TO
mysql_unsupported_compound	DECLARE ... CONDITION, the LOOP statement
mysql_unsupported_utility	EXPLAIN FORMAT=TREE (bare keyword), EXPLAIN ... INTO @var, DESCRIBE tbl 'wildcard'

The goldens also capture every parse gap tracked by the open issues (#14, #15, #17–#21, #23, #28–#30), so those fixes will surface in test diffs automatically.

What came back clean

Optimizer hints (the entire §10.9 hint surface), lexical structure (Chapter 11, except dollar quoting), character sets (Chapter 12), partitioning (Chapter 26), and most of the type grammar all parse — they contributed no groups. Probes that turned out to be invalid or obsolete syntax (NOT MEMBER OF, HANDLER ... READ LAST without an index, RENAME TABLES, SHOW MASTER LOGS, DISABLE ON SLAVE) were excluded rather than recorded as gaps.

Test plan

• go test ./... -count=1 -timeout 120s passes with the new groups
• Every case in the new groups is an error golden (verified none silently parse)

🤖 Generated with Claude Code

https://claude.ai/code/session_01LUq2EgtMGE5ARXusR8mvDY

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