message: Update flatbuffers library
  Includes a patch which fixes implicit double promotion causing issues on some platforms.
diff: @@ -9,11 +9,11 @@ GEMMLOWP_URL := "https://github.com/google/gemmlowp/archive/719139ce755a0f31cbf1
  GEMMLOWP_MD5 := "7e8191b24853d75de2af87622ad293ba"
  ifeq ($(HOST_OS),windows)
  - FLATBUFFERS_URL := "http://mirror.tensorflow.org/github.com/google/flatbuffers/archive/v1.12.0.zip"
  - FLATBUFFERS_MD5 := "a1afdbf114dec01a861c1b8c917d0fc7"
  + FLATBUFFERS_URL := "http://mirror.tensorflow.org/github.com/google/flatbuffers/archive/dca12522a9f9e37f126ab925fd385c807ab4f84e.zip"
  + FLATBUFFERS_MD5 := "aa9adc93eb9b33fa1a2a90969e48baee"
  else
  - FLATBUFFERS_URL := "http://mirror.tensorflow.org/github.com/google/flatbuffers/archive/v1.12.0.tar.gz"
  - FLATBUFFERS_MD5 := "c62ffefb3d4548b127cca14ce047f16c"
  + FLATBUFFERS_URL := "http://mirror.tensorflow.org/github.com/google/flatbuffers/archive/dca12522a9f9e37f126ab925fd385c807ab4f84e.tar.gz"
  + FLATBUFFERS_MD5 := "dfa0ac3073b78ddacdcacf8ca189be91"
  endif
  ifeq ($(HOST_OS),osx)
  