editions: minor fix to resolve editions features correctly

+ The previous commit forgot to resolve the LegacyRequired feature

Change-Id: I05a2847be3d52277c65df004363ea3c87944364e
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/555976
Reviewed-by: Michael Stapelberg <stapelberg@google.com>
Auto-Submit: Lasse Folger <lassefolger@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
diff --git a/internal/filedesc/desc.go b/internal/filedesc/desc.go
index 7b6ab05..1ffdf56 100644
--- a/internal/filedesc/desc.go
+++ b/internal/filedesc/desc.go
@@ -80,6 +80,9 @@
 		// IsFieldPresence is true if field_presence is EXPLICIT
 		// https://protobuf.dev/editions/features/#field_presence
 		IsFieldPresence bool
+		// IsFieldPresence is true if field_presence is LEGACY_REQUIRED
+		// https://protobuf.dev/editions/features/#field_presence
+		IsLegacyRequired bool
 		// IsOpenEnum is true if enum_type is OPEN
 		// https://protobuf.dev/editions/features/#enum_type
 		IsOpenEnum bool
diff --git a/reflect/protodesc/editions.go b/reflect/protodesc/editions.go
index 70cd4e5..50e05c6 100644
--- a/reflect/protodesc/editions.go
+++ b/reflect/protodesc/editions.go
@@ -105,6 +105,7 @@
 	if fp := child.FieldPresence; fp != nil {
 		parentFS.IsFieldPresence = *fp == descriptorpb.FeatureSet_LEGACY_REQUIRED ||
 			*fp == descriptorpb.FeatureSet_EXPLICIT
+		parentFS.IsLegacyRequired = *fp == descriptorpb.FeatureSet_LEGACY_REQUIRED
 	}
 	if et := child.EnumType; et != nil {
 		parentFS.IsOpenEnum = *et == descriptorpb.FeatureSet_OPEN