message: [CMake] Split copying of Swift/Clang headers
  This should result in less merge conflicts with upstream lldb.
diff: @@ -118,9 +118,13 @@ if(NOT IOS)
  COMMAND ${CMAKE_COMMAND} -E copy_directory
  ${clang_resource_headers_dir}
  $<TARGET_FILE_DIR:liblldb>/Resources/Clang/include
  + COMMENT "LLDB.framework: copy clang vendor-specific headers"
  + )
  +
  + add_custom_command(TARGET liblldb POST_BUILD
  COMMAND ${CMAKE_COMMAND} -E copy_directory
  ${SWIFT_BINARY_DIR}/lib/swift
  $<TARGET_FILE_DIR:liblldb>/Resources/Swift
  - COMMENT "LLDB.framework: copy clang vendor-specific headers"
  + COMMENT "LLDB.framework: copy Swift vendor-specific headers"
  )
  endif()
  