upb: tag _upb_Message_GetOrCreateExtension() as UPB_PRIVATE()

PiperOrigin-RevId: 600653849
diff --git a/protos/protos.cc b/protos/protos.cc
index 7296575..fde6120 100644
--- a/protos/protos.cc
+++ b/protos/protos.cc
@@ -180,11 +180,6 @@
 absl::Status SetExtension(upb_Message* message, upb_Arena* message_arena,
                           const upb_MiniTableExtension* ext,
                           const upb_Message* extension) {
-  upb_Extension* msg_ext =
-      _upb_Message_GetOrCreateExtension(message, ext, message_arena);
-  if (!msg_ext) {
-    return MessageAllocationError();
-  }
   // Clone extension into target message arena.
   extension = DeepClone(extension, upb_MiniTableExtension_GetSubMessage(ext),
                         message_arena);
diff --git a/upb/message/copy.c b/upb/message/copy.c
index 485d40a..5d77ab8 100644
--- a/upb/message/copy.c
+++ b/upb/message/copy.c
@@ -259,8 +259,8 @@
   for (size_t i = 0; i < ext_count; ++i) {
     const upb_Extension* msg_ext = &ext[i];
     const upb_MiniTableField* field = &msg_ext->ext->UPB_PRIVATE(field);
-    upb_Extension* dst_ext =
-        _upb_Message_GetOrCreateExtension(dst, msg_ext->ext, arena);
+    upb_Extension* dst_ext = UPB_PRIVATE(_upb_Message_GetOrCreateExtension)(
+        dst, msg_ext->ext, arena);
     if (!dst_ext) return NULL;
     if (upb_MiniTableField_IsScalar(field)) {
       if (!upb_Clone_ExtensionValue(msg_ext->ext, msg_ext, dst_ext, arena)) {
diff --git a/upb/message/internal/accessors.h b/upb/message/internal/accessors.h
index 7e73b4a..7043118 100644
--- a/upb/message/internal/accessors.h
+++ b/upb/message/internal/accessors.h
@@ -284,7 +284,8 @@
     struct upb_Message* msg, const upb_MiniTableExtension* mt_ext,
     const void* val, upb_Arena* a) {
   UPB_ASSERT(a);
-  struct upb_Extension* ext = _upb_Message_GetOrCreateExtension(msg, mt_ext, a);
+  struct upb_Extension* ext =
+      UPB_PRIVATE(_upb_Message_GetOrCreateExtension)(msg, mt_ext, a);
   if (!ext) return false;
   UPB_PRIVATE(_upb_MiniTableField_DataCopy)
   (&mt_ext->UPB_PRIVATE(field), &ext->data, val);
diff --git a/upb/message/internal/extension.c b/upb/message/internal/extension.c
index c48edf7..de6e695 100644
--- a/upb/message/internal/extension.c
+++ b/upb/message/internal/extension.c
@@ -47,7 +47,7 @@
   }
 }
 
-struct upb_Extension* _upb_Message_GetOrCreateExtension(
+struct upb_Extension* UPB_PRIVATE(_upb_Message_GetOrCreateExtension)(
     struct upb_Message* msg, const upb_MiniTableExtension* e, upb_Arena* a) {
   struct upb_Extension* ext =
       (struct upb_Extension*)UPB_PRIVATE(_upb_Message_Getext)(msg, e);
diff --git a/upb/message/internal/extension.h b/upb/message/internal/extension.h
index c0c2bc4..7786f05 100644
--- a/upb/message/internal/extension.h
+++ b/upb/message/internal/extension.h
@@ -40,7 +40,7 @@
 // Adds the given extension data to the given message.
 // |ext| is copied into the message instance.
 // This logically replaces any previously-added extension with this number.
-struct upb_Extension* _upb_Message_GetOrCreateExtension(
+struct upb_Extension* UPB_PRIVATE(_upb_Message_GetOrCreateExtension)(
     struct upb_Message* msg, const upb_MiniTableExtension* ext,
     upb_Arena* arena);
 
diff --git a/upb/message/promote.c b/upb/message/promote.c
index c1442d6..ef42159 100644
--- a/upb/message/promote.c
+++ b/upb/message/promote.c
@@ -99,7 +99,8 @@
   }
   upb_Message* extension_msg = parse_result.message;
   // Add to extensions.
-  upb_Extension* ext = _upb_Message_GetOrCreateExtension(msg, ext_table, arena);
+  upb_Extension* ext =
+      UPB_PRIVATE(_upb_Message_GetOrCreateExtension)(msg, ext_table, arena);
   if (!ext) {
     return kUpb_GetExtension_OutOfMemory;
   }
diff --git a/upb/wire/decode.c b/upb/wire/decode.c
index 2c7626e..07bb8cb 100644
--- a/upb/wire/decode.c
+++ b/upb/wire/decode.c
@@ -815,7 +815,7 @@
     upb_Decoder* d, upb_Message* msg, const upb_MiniTableExtension* item_mt,
     const char* data, uint32_t size) {
   upb_Extension* ext =
-      _upb_Message_GetOrCreateExtension(msg, item_mt, &d->arena);
+      UPB_PRIVATE(_upb_Message_GetOrCreateExtension)(msg, item_mt, &d->arena);
   if (UPB_UNLIKELY(!ext)) {
     _upb_Decoder_ErrorJmp(d, kUpb_DecodeStatus_OutOfMemory);
   }
@@ -1169,8 +1169,8 @@
   if (UPB_UNLIKELY(mode & kUpb_LabelFlags_IsExtension)) {
     const upb_MiniTableExtension* ext_layout =
         (const upb_MiniTableExtension*)field;
-    upb_Extension* ext =
-        _upb_Message_GetOrCreateExtension(msg, ext_layout, &d->arena);
+    upb_Extension* ext = UPB_PRIVATE(_upb_Message_GetOrCreateExtension)(
+        msg, ext_layout, &d->arena);
     if (UPB_UNLIKELY(!ext)) {
       _upb_Decoder_ErrorJmp(d, kUpb_DecodeStatus_OutOfMemory);
     }