message: Try to add fPIC to gtest.
diff: @@ -10,7 +10,8 @@ else()
  "https://github.com/google/googletest.git"
  "df428ec11891f12c81e2872c0432e342b5403a34"
  # Work around the linking errors when compiling gtest with CUDA
  - "-Dgtest_disable_pthreads=ON")
  + "-Dgtest_disable_pthreads=ON"
  + "-DCMAKE_CXX_FLAGS=-fPIC")
  endif()
  ginkgo_add_external_target(GTest::GTest gtest src/googletest/include build/googlemock/gtest
  