0.42.0

Breaking changes

• Remove acceptUnsupportedGrammar option & drop UnsupportedGrammarStmt node (9007110)
• Rename BlockStmt.declareClause to .declare (f7ab9e8)
• Combine ExecuteIntoClause within IntoVariablesClause (e814b32, d3b73dc)
• Move IntoVariablesClause to AllOtherClauses (8d7edca)
• Parse EXECUTE in PL/pgSQL as ExecuteImmediateStmt (44e94b9)

PL/pgSQL parsing improvements

• Support declaring aliases: .. ALIAS FOR ..
• Support MERGE / DELETE / UPDATE / INSERT ... INTO variables
• Support INTO STRICT
• Parse INTO clause differently in PostgreSQL and PL/pgSQL
• Support PERFORM-statement in PL/pgSQL (parsed as SELECT just with different keyword)