Add C++ support for using external FD
diff --git a/tools/run_tests/sources_and_headers.json b/tools/run_tests/sources_and_headers.json
index 782aa37..fe6d3a2 100644
--- a/tools/run_tests/sources_and_headers.json
+++ b/tools/run_tests/sources_and_headers.json
@@ -6435,6 +6435,7 @@
       "include/grpc++/client_context.h", 
       "include/grpc++/completion_queue.h", 
       "include/grpc++/create_channel.h", 
+      "include/grpc++/create_channel_posix.h", 
       "include/grpc++/generic/async_generic_service.h", 
       "include/grpc++/generic/generic_stub.h", 
       "include/grpc++/grpc++.h", 
@@ -6462,6 +6463,7 @@
       "include/grpc++/server.h", 
       "include/grpc++/server_builder.h", 
       "include/grpc++/server_context.h", 
+      "include/grpc++/server_posix.h", 
       "include/grpc++/support/async_stream.h", 
       "include/grpc++/support/async_unary_call.h", 
       "include/grpc++/support/byte_buffer.h", 
@@ -6487,6 +6489,7 @@
       "include/grpc++/client_context.h", 
       "include/grpc++/completion_queue.h", 
       "include/grpc++/create_channel.h", 
+      "include/grpc++/create_channel_posix.h", 
       "include/grpc++/generic/async_generic_service.h", 
       "include/grpc++/generic/generic_stub.h", 
       "include/grpc++/grpc++.h", 
@@ -6514,6 +6517,7 @@
       "include/grpc++/server.h", 
       "include/grpc++/server_builder.h", 
       "include/grpc++/server_context.h", 
+      "include/grpc++/server_posix.h", 
       "include/grpc++/support/async_stream.h", 
       "include/grpc++/support/async_unary_call.h", 
       "include/grpc++/support/byte_buffer.h", 
@@ -6531,6 +6535,7 @@
       "src/cpp/client/create_channel.cc", 
       "src/cpp/client/create_channel_internal.cc", 
       "src/cpp/client/create_channel_internal.h", 
+      "src/cpp/client/create_channel_posix.cc", 
       "src/cpp/client/credentials.cc", 
       "src/cpp/client/generic_stub.cc", 
       "src/cpp/client/insecure_credentials.cc", 
@@ -6548,6 +6553,7 @@
       "src/cpp/server/server_builder.cc", 
       "src/cpp/server/server_context.cc", 
       "src/cpp/server/server_credentials.cc", 
+      "src/cpp/server/server_posix.cc", 
       "src/cpp/server/thread_pool_interface.h", 
       "src/cpp/util/byte_buffer.cc", 
       "src/cpp/util/slice.cc",