chore: import upstream snapshot with attribution

tensorflow/lite/tools/cmake/modules/farmhash/CMakeLists.txt

@@ -0,0 +1,50 @@
+#
+# Copyright 2020 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+project(farmhash CXX)
+
+set(FARMHASH_SOURCE_DIR "" CACHE PATH
+  "Directory that contains the farmhash project"
+)
+if(NOT FARMHASH_SOURCE_DIR)
+  message(FATAL_ERROR "Must specify source directory")
+endif()
+
+# Transcribed from farmhash/src/Makefile.am
+include(CheckCXXSourceCompiles)
+check_cxx_source_compiles(
+  "int main(int argc, char* argv[]) { return (int)__builtin_expect(0, 0); }"
+  FARMHASH_HAS_BUILTIN_EXPECT
+)
+
+add_library(farmhash
+  "${FARMHASH_SOURCE_DIR}/src/farmhash.cc"
+  "${FARMHASH_SOURCE_DIR}/src/farmhash.h"
+)
+set_target_properties(farmhash PROPERTIES PUBLIC_HEADER "${FARMHASH_SOURCE_DIR}/src/farmhash.h")
+target_include_directories(farmhash PUBLIC $<BUILD_INTERFACE:${FARMHASH_SOURCE_DIR}/src> $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
+if(NOT FARMHASH_HAS_BUILTIN_EXPECT)
+  target_compile_definitions(farmhash PUBLIC -DFARMHASH_NO_BUILTIN_EXPECT)
+endif()
+
+if(TFLITE_ENABLE_INSTALL)
+  install(
+    TARGETS farmhash
+    EXPORT tensorflow-liteTargets
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    PUBLIC_HEADER DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+  )
+endif()