GeezerVison

Fixes #2447

Problem

TYPE is a non-reserved keyword in MySQL 8.0, so this is valid MySQL syntax without quoting:

ALTER TABLE nullable_tbl DROP COLUMN type;

but it fails with ParseException: Encountered unexpected token: "type" "TYPE", while the same identifier parses fine in a SELECT (via RelObjectName(), since K_TYPE is inside the non-reserved word range).

Fix

Adds K_TYPE to KeywordOrIdentifier(), following the exact same approach as #2340 (which added K_DATA for the same class of bug, see #2339).

This covers all KeywordOrIdentifier() call sites: DROP [COLUMN], RENAME [COLUMN], and CHANGE [COLUMN].

Tests

• testAlterTableDropColumnIssue2447 — ALTER TABLE test DROP COLUMN type
• testAlterTableChangeColumnIssue2447 — ALTER TABLE tb_test CHANGE type INT (10)
• testAlterTableRenameColumnIssue2447 — ALTER TABLE test_table RENAME COLUMN type TO type2

Full test suite passes (4646 tests, 0 failures). JavaCC parser generation reports the same pre-existing warnings as master (#2403) with no new choice conflicts.