message: Install lldb's SB headers (pr36630)
  These were removed in r309021 in what looks like an accidentally
  committed change. This brings them back.
  I also rename the header component to lldb-headers (instead of
  lldb_headers) to match the llvm style and add a special
  install-lldb-headers target, which installs just the headers.
diff: @@ -277,27 +277,31 @@ include_directories(BEFORE
  if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
  install(DIRECTORY include/
  - COMPONENT lldb_headers
  + COMPONENT lldb-headers
  DESTINATION include
  FILES_MATCHING
  PATTERN "*.h"
  PATTERN ".svn" EXCLUDE
  PATTERN ".cmake" EXCLUDE
  PATTERN "Config.h" EXCLUDE
  - PATTERN "lldb-*.h" EXCLUDE
  - PATTERN "API/*.h" EXCLUDE
  )
  install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/include/
  - COMPONENT lldb_headers
  + COMPONENT lldb-headers
  DESTINATION include
  FILES_MATCHING
  PATTERN "*.h"
  PATTERN ".svn" EXCLUDE
  PATTERN ".cmake" EXCLUDE
  - PATTERN "lldb-*.h" EXCLUDE
  - PATTERN "API/*.h" EXCLUDE
  )
  +
  + add_custom_target(lldb-headers)
  + set_target_properties(lldb-headers PROPERTIES FOLDER "Misc")
  +
  + if (NOT CMAKE_CONFIGURATION_TYPES)
  + add_llvm_install_targets(install-lldb-headers
  + COMPONENT lldb-headers)
  + endif()
  endif()
  if (NOT LIBXML2_FOUND AND NOT (CMAKE_SYSTEM_NAME MATCHES "Windows"))
  