[gn build] Port 8b64cd8

Author: pcc

llvm/utils/gn/secondary/lldb/tools/lldb-dap/BUILD.gn

@@ -44,6 +44,7 @@ static_library("lib") {
  "Handler/InitializeRequestHandler.cpp",
  "Handler/LaunchRequestHandler.cpp",
  "Handler/LocationsRequestHandler.cpp",
+ "Handler/ModuleSymbolsRequestHandler.cpp",
  "Handler/ModulesRequestHandler.cpp",
  "Handler/NextRequestHandler.cpp",
  "Handler/PauseRequestHandler.cpp",