Fix serialization.

Fix serialization for Serialization/differentia{ble,ting}_attr.swift.

Author: dan-zheng

lib/Serialization/Serialization.cpp

@@ -789,6 +789,7 @@ void Serializer::writeBlockInfoBlock() {
   BLOCK_RECORD(sil_block, SIL_INST_LINEAR_FUNCTION);
   BLOCK_RECORD(sil_block, SIL_INST_DIFFERENTIABLE_FUNCTION_EXTRACT);
   BLOCK_RECORD(sil_block, SIL_INST_LINEAR_FUNCTION_EXTRACT);
+  BLOCK_RECORD(sil_block, SIL_DIFFERENTIABILITY_WITNESS);
   // SWIFT_ENABLE_TENSORFLOW END
 
   // These layouts can exist in both decl blocks and sil blocks.
@@ -829,6 +830,7 @@ void Serializer::writeBlockInfoBlock() {
   BLOCK_RECORD(sil_index_block, SIL_DEFAULT_WITNESS_TABLE_OFFSETS);
   BLOCK_RECORD(sil_index_block, SIL_PROPERTY_OFFSETS);
   // SWIFT_ENABLE_TENSORFLOW
+  BLOCK_RECORD(sil_index_block, SIL_DIFFERENTIABILITY_WITNESS_NAMES);
   BLOCK_RECORD(sil_index_block, SIL_DIFFERENTIABILITY_WITNESS_OFFSETS);
   // SWIFT_ENABLE_TENSORFLOW END