tree: include gist into enum comparison assertion

In theory, the plan gist should already be included in all assertion
failures, but it doesn't happen in practice. Let's include it explicitly
(if it is present in the context) into the enum mismatched version
comparison error to help with tracking it down.

Release note: None

Author: yuzefovich

pkg/sql/conn_executor.go

@@ -4854,4 +4854,5 @@ func init() {
 	logcrash.RegisterTagFn("gist", func(ctx context.Context) string {
 		return planGistFromCtx(ctx)
 	})
+	tree.PlanGistFromCtx = planGistFromCtx
 }

pkg/sql/sem/tree/datum.go

@@ -5474,6 +5474,10 @@ func (d *DEnum) ResolvedType() *types.T {
 	return d.EnumTyp
 }
 
+// PlanCistFromCtx returns the plan gist if it is stored in the context. It is
+// injected from the sql package to avoid import cycle.
+var PlanGistFromCtx func(context.Context) string
+
 // Compare implements the Datum interface.
 func (d *DEnum) Compare(ctx context.Context, cmpCtx CompareContext, other Datum) (int, error) {
 	if other == DNull {
@@ -5491,10 +5495,16 @@ func (d *DEnum) Compare(ctx context.Context, cmpCtx CompareContext, other Datum)
 
 	// We should never be comparing two different versions of the same enum.
 	if v.EnumTyp.TypeMeta.Version != d.EnumTyp.TypeMeta.Version {
+		var gist redact.SafeString
+		if PlanGistFromCtx != nil {
+			// Plan gist, by construction, doesn't contain any PII, so it's a
+			// safe string.
+			gist = redact.SafeString(PlanGistFromCtx(ctx))
+		}
 		panic(errors.AssertionFailedf(
-			"comparison of two different versions of enum %s oid %d: versions %d and %d",
+			"comparison of two different versions of enum %s oid %d: versions %d and %d, gist %q",
 			d.EnumTyp.SQLStringForError(), errors.Safe(d.EnumTyp.Oid()), d.EnumTyp.TypeMeta.Version,
-			v.EnumTyp.TypeMeta.Version,
+			v.EnumTyp.TypeMeta.Version, gist,
 		))
 	}