Serialization: Fix serialization of layout constraints

Author: slavapestov

lib/Serialization/Serialization.cpp

@@ -657,6 +657,8 @@ void Serializer::writeBlockInfoBlock() {
                               decls_block::GENERIC_PARAM);
   BLOCK_RECORD_WITH_NAMESPACE(sil_block,
                               decls_block::GENERIC_REQUIREMENT);
+  BLOCK_RECORD_WITH_NAMESPACE(sil_block,
+                              decls_block::LAYOUT_REQUIREMENT);
 
   BLOCK(SIL_INDEX_BLOCK);
   BLOCK_RECORD(sil_index_block, SIL_FUNC_NAMES);
@@ -3528,6 +3530,7 @@ void Serializer::writeAllDeclsAndTypes() {
   registerDeclTypeAbbr<GenericParamListLayout>();
   registerDeclTypeAbbr<GenericParamLayout>();
   registerDeclTypeAbbr<GenericRequirementLayout>();
+  registerDeclTypeAbbr<LayoutRequirementLayout>();
   registerDeclTypeAbbr<GenericEnvironmentLayout>();
   registerDeclTypeAbbr<SILGenericEnvironmentLayout>();