Index: llvm/utils/TableGen/Common/CMakeLists.txt
--- llvm/utils/TableGen/Common/CMakeLists.txt.orig
+++ llvm/utils/TableGen/Common/CMakeLists.txt
@@ -44,6 +44,8 @@ add_llvm_library(LLVMTableGenCommon STATIC OBJECT EXCL
   intrinsics_gen
   )
 
+add_definitions(-D_LIBCPP_USE_LOWER_DEQUE_BLOCK_SIZE)
+
 # Users may include its headers as "Common/*.h"
 target_include_directories(LLVMTableGenCommon
   PUBLIC
