Import prebuilt clang toolchain for linux.
diff --git a/linux-x64/clang/lib64/cmake/llvm/TableGen.cmake b/linux-x64/clang/lib64/cmake/llvm/TableGen.cmake
new file mode 100644
index 0000000..d1afcb4
--- /dev/null
+++ b/linux-x64/clang/lib64/cmake/llvm/TableGen.cmake
@@ -0,0 +1,183 @@
+# LLVM_TARGET_DEFINITIONS must contain the name of the .td file to process.
+# Extra parameters for `tblgen' may come after `ofn' parameter.
+# Adds the name of the generated file to TABLEGEN_OUTPUT.
+
+include(LLVMExternalProjectUtils)
+
+if(LLVM_MAIN_INCLUDE_DIR)
+  set(LLVM_TABLEGEN_FLAGS -I ${LLVM_MAIN_INCLUDE_DIR})
+endif()
+
+function(tablegen project ofn)
+  # Validate calling context.
+  if(NOT ${project}_TABLEGEN_EXE)
+    message(FATAL_ERROR "${project}_TABLEGEN_EXE not set")
+  endif()
+
+  # Use depfile instead of globbing arbitrary *.td(s)
+  # DEPFILE is available for Ninja Generator with CMake>=3.7.
+  if(CMAKE_GENERATOR STREQUAL "Ninja" AND NOT CMAKE_VERSION VERSION_LESS 3.7)
+    # Make output path relative to build.ninja, assuming located on
+    # ${CMAKE_BINARY_DIR}.
+    # CMake emits build targets as relative paths but Ninja doesn't identify
+    # absolute path (in *.d) as relative path (in build.ninja)
+    # Note that tblgen is executed on ${CMAKE_BINARY_DIR} as working directory.
+    file(RELATIVE_PATH ofn_rel
+      ${CMAKE_BINARY_DIR} ${CMAKE_CURRENT_BINARY_DIR}/${ofn})
+    set(additional_cmdline
+      -o ${ofn_rel}.tmp
+      -d ${ofn_rel}.d
+      WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+      DEPFILE ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.d
+      )
+    set(local_tds)
+    set(global_tds)
+  else()
+    file(GLOB local_tds "*.td")
+    file(GLOB_RECURSE global_tds "${LLVM_MAIN_INCLUDE_DIR}/llvm/*.td")
+    set(additional_cmdline
+      -o ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.tmp
+      )
+  endif()
+
+  if (IS_ABSOLUTE ${LLVM_TARGET_DEFINITIONS})
+    set(LLVM_TARGET_DEFINITIONS_ABSOLUTE ${LLVM_TARGET_DEFINITIONS})
+  else()
+    set(LLVM_TARGET_DEFINITIONS_ABSOLUTE
+      ${CMAKE_CURRENT_SOURCE_DIR}/${LLVM_TARGET_DEFINITIONS})
+  endif()
+  if (LLVM_ENABLE_DAGISEL_COV)
+    list(FIND ARGN "-gen-dag-isel" idx)
+    if( NOT idx EQUAL -1 )
+      list(APPEND LLVM_TABLEGEN_FLAGS "-instrument-coverage")
+    endif()
+  endif()
+  if (LLVM_ENABLE_GISEL_COV)
+    list(FIND ARGN "-gen-global-isel" idx)
+    if( NOT idx EQUAL -1 )
+      list(APPEND LLVM_TABLEGEN_FLAGS "-instrument-gisel-coverage")
+      list(APPEND LLVM_TABLEGEN_FLAGS "-gisel-coverage-file=${LLVM_GISEL_COV_PREFIX}all")
+    endif()
+  endif()
+
+  # We need both _TABLEGEN_TARGET and _TABLEGEN_EXE in the  DEPENDS list
+  # (both the target and the file) to have .inc files rebuilt on
+  # a tablegen change, as cmake does not propagate file-level dependencies
+  # of custom targets. See the following ticket for more information:
+  # https://cmake.org/Bug/view.php?id=15858
+  # The dependency on both, the target and the file, produces the same
+  # dependency twice in the result file when
+  # ("${${project}_TABLEGEN_TARGET}" STREQUAL "${${project}_TABLEGEN_EXE}")
+  # but lets us having smaller and cleaner code here.
+  add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.tmp
+    # Generate tablegen output in a temporary file.
+    COMMAND ${${project}_TABLEGEN_EXE} ${ARGN} -I ${CMAKE_CURRENT_SOURCE_DIR}
+    ${LLVM_TABLEGEN_FLAGS}
+    ${LLVM_TARGET_DEFINITIONS_ABSOLUTE}
+    ${additional_cmdline}
+    # The file in LLVM_TARGET_DEFINITIONS may be not in the current
+    # directory and local_tds may not contain it, so we must
+    # explicitly list it here:
+    DEPENDS ${${project}_TABLEGEN_TARGET} ${${project}_TABLEGEN_EXE}
+      ${local_tds} ${global_tds}
+    ${LLVM_TARGET_DEFINITIONS_ABSOLUTE}
+    COMMENT "Building ${ofn}..."
+    )
+  add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/${ofn}
+    # Only update the real output file if there are any differences.
+    # This prevents recompilation of all the files depending on it if there
+    # aren't any.
+    COMMAND ${CMAKE_COMMAND} -E copy_if_different
+        ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.tmp
+        ${CMAKE_CURRENT_BINARY_DIR}/${ofn}
+    DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/${ofn}.tmp
+    COMMENT "Updating ${ofn}..."
+    )
+
+  # `make clean' must remove all those generated files:
+  set_property(DIRECTORY APPEND
+    PROPERTY ADDITIONAL_MAKE_CLEAN_FILES ${ofn}.tmp ${ofn})
+
+  set(TABLEGEN_OUTPUT ${TABLEGEN_OUTPUT} ${CMAKE_CURRENT_BINARY_DIR}/${ofn} PARENT_SCOPE)
+  set_source_files_properties(${CMAKE_CURRENT_BINARY_DIR}/${ofn} PROPERTIES
+    GENERATED 1)
+endfunction()
+
+# Creates a target for publicly exporting tablegen dependencies.
+function(add_public_tablegen_target target)
+  if(NOT TABLEGEN_OUTPUT)
+    message(FATAL_ERROR "Requires tablegen() definitions as TABLEGEN_OUTPUT.")
+  endif()
+  add_custom_target(${target}
+    DEPENDS ${TABLEGEN_OUTPUT})
+  if(LLVM_COMMON_DEPENDS)
+    add_dependencies(${target} ${LLVM_COMMON_DEPENDS})
+  endif()
+  set_target_properties(${target} PROPERTIES FOLDER "Tablegenning")
+  set(LLVM_COMMON_DEPENDS ${LLVM_COMMON_DEPENDS} ${target} PARENT_SCOPE)
+endfunction()
+
+macro(add_tablegen target project)
+  set(${target}_OLD_LLVM_LINK_COMPONENTS ${LLVM_LINK_COMPONENTS})
+  set(LLVM_LINK_COMPONENTS ${LLVM_LINK_COMPONENTS} TableGen)
+
+  # CMake-3.9 doesn't let compilation units depend on their dependent libraries.
+  if(NOT (CMAKE_GENERATOR STREQUAL "Ninja" AND NOT CMAKE_VERSION VERSION_LESS 3.9) AND NOT XCODE)
+    # FIXME: It leaks to user, callee of add_tablegen.
+    set(LLVM_ENABLE_OBJLIB ON)
+  endif()
+
+  add_llvm_executable(${target} DISABLE_LLVM_LINK_LLVM_DYLIB ${ARGN})
+  set(LLVM_LINK_COMPONENTS ${${target}_OLD_LLVM_LINK_COMPONENTS})
+
+  set(${project}_TABLEGEN "${target}" CACHE
+      STRING "Native TableGen executable. Saves building one when cross-compiling.")
+
+  # Upgrade existing LLVM_TABLEGEN setting.
+  if(${project} STREQUAL LLVM)
+    if(${LLVM_TABLEGEN} STREQUAL tblgen)
+      set(LLVM_TABLEGEN "${target}" CACHE
+          STRING "Native TableGen executable. Saves building one when cross-compiling."
+          FORCE)
+    endif()
+  endif()
+
+  # Effective tblgen executable to be used:
+  set(${project}_TABLEGEN_EXE ${${project}_TABLEGEN} PARENT_SCOPE)
+  set(${project}_TABLEGEN_TARGET ${${project}_TABLEGEN} PARENT_SCOPE)
+
+  if(LLVM_USE_HOST_TOOLS)
+    if( ${${project}_TABLEGEN} STREQUAL "${target}" )
+      if (NOT CMAKE_CONFIGURATION_TYPES)
+        set(${project}_TABLEGEN_EXE "${LLVM_NATIVE_BUILD}/bin/${target}")
+      else()
+        set(${project}_TABLEGEN_EXE "${LLVM_NATIVE_BUILD}/Release/bin/${target}")
+      endif()
+      set(${project}_TABLEGEN_EXE ${${project}_TABLEGEN_EXE} PARENT_SCOPE)
+
+      llvm_ExternalProject_BuildCmd(tblgen_build_cmd ${target}
+                                    ${LLVM_NATIVE_BUILD}
+                                    CONFIGURATION Release)
+      add_custom_command(OUTPUT ${${project}_TABLEGEN_EXE}
+        COMMAND ${tblgen_build_cmd}
+        DEPENDS CONFIGURE_LLVM_NATIVE ${target}
+        WORKING_DIRECTORY ${LLVM_NATIVE_BUILD}
+        COMMENT "Building native TableGen..."
+        USES_TERMINAL)
+      add_custom_target(${project}-tablegen-host DEPENDS ${${project}_TABLEGEN_EXE})
+      set(${project}_TABLEGEN_TARGET ${project}-tablegen-host PARENT_SCOPE)
+    endif()
+  endif()
+
+  if (${project} STREQUAL LLVM AND NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
+    if(${target} IN_LIST LLVM_DISTRIBUTION_COMPONENTS OR
+        NOT LLVM_DISTRIBUTION_COMPONENTS)
+      set(export_to_llvmexports EXPORT LLVMExports)
+    endif()
+
+    install(TARGETS ${target}
+            ${export_to_llvmexports}
+            RUNTIME DESTINATION ${LLVM_TOOLS_INSTALL_DIR})
+  endif()
+  set_property(GLOBAL APPEND PROPERTY LLVM_EXPORTS ${target})
+endmacro()