[Serialization] Bump number of bits for decl/type block id to 9

Author: xedin

lib/Serialization/Serialization.cpp

@@ -5915,7 +5915,7 @@ bool Serializer::writeASTBlockEntitiesIfNeeded(
 }
 
 void Serializer::writeAllDeclsAndTypes() {
-  BCBlockRAII restoreBlock(Out, DECLS_AND_TYPES_BLOCK_ID, 8);
+  BCBlockRAII restoreBlock(Out, DECLS_AND_TYPES_BLOCK_ID, 9);
   using namespace decls_block;
   registerDeclTypeAbbr<BuiltinAliasTypeLayout>();
   registerDeclTypeAbbr<TypeAliasTypeLayout>();