sql: deserialize sequence name for SHOW CREATE FUNCTION

Previously, `SHOW CREATE FUNCTION` returns a function body
with sequence OIDs. This commit deserializes sequence OID
into qualified names.

Release note: None.
Release justification: low risk enhancement.

pkg/sql/crdb_internal.go

@@ -2648,7 +2648,11 @@ CREATE TABLE crdb_internal.create_function_statements (
 			}
 			for i := range treeNode.Options {
 				if body, ok := treeNode.Options[i].(tree.FunctionBodyStr); ok {
-					stmtStrs := strings.Split(string(body), "\n")
+					seqReplacedBody, err := formatQuerySequencesForDisplay(ctx, &p.semaCtx, string(body), true /* multiStmt */)
+					if err != nil {
+						return err
+					}
+					stmtStrs := strings.Split(seqReplacedBody, "\n")
 					for i := range stmtStrs {
 						stmtStrs[i] = "\t" + stmtStrs[i]
 					}

pkg/sql/logictest/testdata/logic_test/udf

@@ -143,7 +143,7 @@ CREATE FUNCTION public.f(IN a test.public.notmyworkday)
     SELECT a FROM test.public.t;
     SELECT b FROM test.public.t@t_idx_b;
     SELECT c FROM test.public.t@t_idx_c;
-    SELECT nextval(114:::REGCLASS);
+    SELECT nextval('public.sq1'::REGCLASS);
 $$
 
 statement error pq: unimplemented: alter function depends on extension not supported.*

pkg/sql/show_create_clauses.go

@@ -167,7 +167,7 @@ func formatViewQueryForDisplay(
 	}
 
 	// Convert sequences referenced by ID in the view back to their names.
-	sequenceReplacedViewQuery, err := formatViewQuerySequencesForDisplay(ctx, semaCtx, typeReplacedViewQuery)
+	sequenceReplacedViewQuery, err := formatQuerySequencesForDisplay(ctx, semaCtx, typeReplacedViewQuery, false /* multiStmt */)
 	if err != nil {
 		log.Warningf(ctx, "error converting sequence IDs to names for view %s (%v): %+v",
 			desc.GetName(), desc.GetID(), err)
@@ -177,11 +177,11 @@ func formatViewQueryForDisplay(
 	return sequenceReplacedViewQuery
 }
 
-// formatViewQuerySequencesForDisplay walks the view query and
+// formatQuerySequencesForDisplay walks the view query and
 // looks for sequence IDs in the statement. If it finds any,
 // it will replace the IDs with the descriptor's fully qualified name.
-func formatViewQuerySequencesForDisplay(
-	ctx context.Context, semaCtx *tree.SemaContext, viewQuery string,
+func formatQuerySequencesForDisplay(
+	ctx context.Context, semaCtx *tree.SemaContext, queries string, multiStmt bool,
 ) (string, error) {
 	replaceFunc := func(expr tree.Expr) (recurse bool, newExpr tree.Expr, err error) {
 		newExpr, err = schemaexpr.ReplaceIDsWithFQNames(ctx, expr, semaCtx)
@@ -191,16 +191,39 @@ func formatViewQuerySequencesForDisplay(
 		return false, newExpr, nil
 	}
 
-	stmt, err := parser.ParseOne(viewQuery)
-	if err != nil {
-		return "", err
+	var stmts tree.Statements
+	if multiStmt {
+		parsedStmts, err := parser.Parse(queries)
+		if err != nil {
+			return "", err
+		}
+		stmts = make(tree.Statements, len(parsedStmts))
+		for i, stmt := range parsedStmts {
+			stmts[i] = stmt.AST
+		}
+	} else {
+		stmt, err := parser.ParseOne(queries)
+		if err != nil {
+			return "", err
+		}
+		stmts = tree.Statements{stmt.AST}
 	}
 
-	newStmt, err := tree.SimpleStmtVisit(stmt.AST, replaceFunc)
-	if err != nil {
-		return "", err
+	fmtCtx := tree.NewFmtCtx(tree.FmtSimple)
+	for i, stmt := range stmts {
+		newStmt, err := tree.SimpleStmtVisit(stmt, replaceFunc)
+		if err != nil {
+			return "", err
+		}
+		if i > 0 {
+			fmtCtx.WriteString("\n")
+		}
+		fmtCtx.FormatNode(newStmt)
+		if multiStmt {
+			fmtCtx.WriteString(";")
+		}
 	}
-	return newStmt.String(), nil
+	return fmtCtx.CloseAndGetString(), nil
 }
 
 // formatViewQueryTypesForDisplay walks the view query and