[mbr] Turn on hot reload for iOS, tvOS and MacCatalyst (#50458)

* [mbr] Turn on hot reload for iOS, tvOS and MacCatalyst

* [mbr] Mark some unused variables with G_GNUC_UNUSED

   Fixes build on MacCatalyst

Author: lambdageek

src/mono/Directory.Build.props

@@ -64,6 +64,7 @@
   <PropertyGroup>
     <!-- default metadata update support for specific platforms -->
     <MonoMetadataUpdate Condition="'$(MonoMetadataUpdate)' == '' and ('$(TargetsAndroid)' == 'true' or '$(TargetsBrowser)' == 'true')">true</MonoMetadataUpdate>
+    <MonoMetadataUpdate Condition="'$(MonoMetadataUpdate)' == '' and ('$(TargetsiOS)' == 'true' or '$(TargetstvOS)' == 'true' or '$(TargetsMacCatalyst)' == 'true')">true</MonoMetadataUpdate>
     <MonoMetadataUpdate Condition="'$(MonoMetadataUpdate)' == ''">false</MonoMetadataUpdate>
   </PropertyGroup>
 </Project>

src/mono/mono/mini/debugger-agent.c

@@ -6421,8 +6421,8 @@ module_apply_changes (MonoImage *image, MonoArray *dmeta, MonoArray *dil, MonoAr
 	int32_t dmeta_len = mono_array_length_internal (dmeta);
 	gpointer dil_bytes = (gpointer)mono_array_addr_internal (dil, char, 0);
 	int32_t dil_len = mono_array_length_internal (dil);
-	gpointer dpdb_bytes = !dpdb ? NULL : (gpointer)mono_array_addr_internal (dpdb, char, 0);
-	int32_t dpdb_len = !dpdb ? 0 : mono_array_length_internal (dpdb);
+	gpointer dpdb_bytes G_GNUC_UNUSED = !dpdb ? NULL : (gpointer)mono_array_addr_internal (dpdb, char, 0);
+	int32_t dpdb_len G_GNUC_UNUSED = !dpdb ? 0 : mono_array_length_internal (dpdb);
 	mono_image_load_enc_delta (image, dmeta_bytes, dmeta_len, dil_bytes, dil_len, error);
 	return is_ok (error);
 #else