Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/lib64/cmake/llvm/AddSphinxTarget.cmake b/linux-x64/clang/lib64/cmake/llvm/AddSphinxTarget.cmake
new file mode 100644
index 0000000..22e3dcb
--- /dev/null
+++ b/linux-x64/clang/lib64/cmake/llvm/AddSphinxTarget.cmake
@@ -0,0 +1,90 @@
+
+# Create sphinx target
+if (LLVM_ENABLE_SPHINX)
+  message(STATUS "Sphinx enabled.")
+  find_package(Sphinx REQUIRED)
+  if (LLVM_BUILD_DOCS AND NOT TARGET sphinx)
+    add_custom_target(sphinx ALL)
+  endif()
+else()
+  message(STATUS "Sphinx disabled.")
+endif()
+
+
+# Handy function for creating the different Sphinx targets.
+#
+# ``builder`` should be one of the supported builders used by
+# the sphinx-build command.
+#
+# ``project`` should be the project name
+function (add_sphinx_target builder project)
+  set(SPHINX_BUILD_DIR "${CMAKE_CURRENT_BINARY_DIR}/${builder}")
+  set(SPHINX_DOC_TREE_DIR "${CMAKE_CURRENT_BINARY_DIR}/_doctrees-${project}-${builder}")
+  set(SPHINX_TARGET_NAME docs-${project}-${builder})
+
+  if (SPHINX_WARNINGS_AS_ERRORS)
+    set(SPHINX_WARNINGS_AS_ERRORS_FLAG "-W")
+  else()
+    set(SPHINX_WARNINGS_AS_ERRORS_FLAG "")
+  endif()
+
+  add_custom_target(${SPHINX_TARGET_NAME}
+                    COMMAND ${SPHINX_EXECUTABLE}
+                            -b ${builder}
+                            -d "${SPHINX_DOC_TREE_DIR}"
+                            -q # Quiet: no output other than errors and warnings.
+                            ${SPHINX_WARNINGS_AS_ERRORS_FLAG} # Treat warnings as errors if requested
+                            "${CMAKE_CURRENT_SOURCE_DIR}" # Source
+                            "${SPHINX_BUILD_DIR}" # Output
+                    COMMENT
+                    "Generating ${builder} Sphinx documentation for ${project} into \"${SPHINX_BUILD_DIR}\"")
+
+  # When "clean" target is run, remove the Sphinx build directory
+  set_property(DIRECTORY APPEND PROPERTY
+               ADDITIONAL_MAKE_CLEAN_FILES
+               "${SPHINX_BUILD_DIR}")
+
+  # We need to remove ${SPHINX_DOC_TREE_DIR} when make clean is run
+  # but we should only add this path once
+  get_property(_CURRENT_MAKE_CLEAN_FILES
+               DIRECTORY PROPERTY ADDITIONAL_MAKE_CLEAN_FILES)
+  list(FIND _CURRENT_MAKE_CLEAN_FILES "${SPHINX_DOC_TREE_DIR}" _INDEX)
+  if (_INDEX EQUAL -1)
+    set_property(DIRECTORY APPEND PROPERTY
+                 ADDITIONAL_MAKE_CLEAN_FILES
+                 "${SPHINX_DOC_TREE_DIR}")
+  endif()
+
+  if (LLVM_BUILD_DOCS)
+    add_dependencies(sphinx ${SPHINX_TARGET_NAME})
+
+    # Handle installation
+    if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+      if (builder STREQUAL man)
+        if (CMAKE_INSTALL_MANDIR)
+          set(INSTALL_MANDIR ${CMAKE_INSTALL_MANDIR}/)
+        else()
+          set(INSTALL_MANDIR share/man/)
+        endif()
+        # FIXME: We might not ship all the tools that these man pages describe
+        install(DIRECTORY "${SPHINX_BUILD_DIR}/" # Slash indicates contents of
+                COMPONENT "${project}-sphinx-man"
+                DESTINATION ${INSTALL_MANDIR}man1)
+
+      elseif (builder STREQUAL html)
+        string(TOUPPER "${project}" project_upper)
+        set(${project_upper}_INSTALL_SPHINX_HTML_DIR "share/doc/${project}/html"
+            CACHE STRING "HTML documentation install directory for ${project}")
+
+        # '/.' indicates: copy the contents of the directory directly into
+        # the specified destination, without recreating the last component
+        # of ${SPHINX_BUILD_DIR} implicitly.
+        install(DIRECTORY "${SPHINX_BUILD_DIR}/."
+                COMPONENT "${project}-sphinx-html"
+                DESTINATION "${${project_upper}_INSTALL_SPHINX_HTML_DIR}")
+      else()
+        message(WARNING Installation of ${builder} not supported)
+      endif()
+    endif()
+  endif()
+endfunction()