Update Oz inlining demo to work with TFLite (#131)

Some minor changes to the inlining demo, just changing all of the info
on using the Tensorflow C library to using TFLite, including adding info
on compilation of the library using the buildbot script.

Author: boomanaiden154

docs/demo/demo.md

@@ -74,19 +74,9 @@ cipd install fuchsia/sysroot/linux-amd64 latest -root ${SYSROOT_DIR}/linux-x64
 ## Set up the correct package versions
 
 We need to make sure the git revision of llvm is one that works with the version
-of the Fuchsia tree. Note that Fuchsia frequently updates their llvm dependency,
-which should mean you could try working at HEAD for both, but the method here is
-safe.
+of the Fuchsia tree.
 
-*Optionally, you can get Fuchsia to the version we used we wrote this guide:*
-
-```
-cd ${FUCHSIA_SRCDIR}
-jiri update -gc ~/ml-compiler-opt/docs/demo/fuchsia.xml
-```
-
-Either way - i.e. you can skip the step above to be at Fuchsia HEAD - to get the
-git hash at which we know this version of Fuchsia will build, do:
+To get the git hash at which we know this version of Fuchsia will build, do:
 
 ```
 cd ${FUCHSIA_SRCDIR}
@@ -108,20 +98,11 @@ This is this repository.
 
 ### Tensorflow dependencies
 
-See also [the build bot script](../../buildbot/buildbot_init.sh)
+We need to install all of the Python dependencies for this repository, setup
+some environment variables for the AOT compiler, and also build the TFLite
+dependency to compile LLVM in MLGO development mode.
 
-**NOTE:** The versioning of Tensorflow is pretty important in order to get a
-functioning build with the demo setup. Building with a Tensorflow pip
-package above v2.7.0 will cause the build to fail as well as building with
-a libtensorflow version above v1.15.x. Versions of the Tensorflow pip package
-under v2.8.0 don't have any available wheels for Python 3.10, so if you
-are on a more recent distro (eg Ubuntu 22.04) that has Python 3.10, you will
-run into version compatibility issues between the required Tensorflow version
-and the available Python version (pip will refuse to install Tensorflow) trying
-to install the required python packages from `ml-compiler-opt/requirements.txt`.
-To mitigate this, either use a distro with a compatible python version
-(eg Ubuntu 20.04), or your preferred flavor of python virtual environment
-to utilize a compatible Python version.
+See also [the build bot script](../../buildbot/buildbot_init.sh)
 
 ```shell
 cd
@@ -133,18 +114,18 @@ TF_PIP=$(python3 -m pip show tensorflow | grep Location | cut -d ' ' -f 2)
 
 export TENSORFLOW_AOT_PATH="${TF_PIP}/tensorflow"
 
-mkdir ~/tensorflow
-export TENSORFLOW_C_LIB_PATH=~/tensorflow
-wget --quiet https://storage.googleapis.com/tensorflow/libtensorflow/libtensorflow-cpu-linux-x86_64-1.15.0.tar.gz
-tar xfz libtensorflow-cpu-linux-x86_64-1.15.0.tar.gz -C "${TENSORFLOW_C_LIB_PATH}"
+export TFLITE_PATH=~/tflite
+mkdir ${TFLITE_PATH}
+cd ${TFLITE_PATH}
+~/ml-compiler-opt/buildbot/build_tflite.sh
 ```
 
 ## Build LLVM
 
 Build LLVM with the 'development' ML mode, and additional
 Fuchsia-specific settings:
 
-```
+```shell
 cd ${LLVM_SRCDIR}
 mkdir build
 cd build
@@ -154,9 +135,9 @@ cmake -G Ninja \
   -DLINUX_aarch64-unknown-linux-gnu_SYSROOT=${SYSROOT_DIR}/linux-arm64 \
   -DFUCHSIA_SDK=${IDK_DIR} \
   -DCMAKE_INSTALL_PREFIX= \
-  -DTENSORFLOW_C_LIB_PATH=${TENSORFLOW_C_LIB_PATH} \
   -DCMAKE_INSTALL_RPATH_USE_LINK_PATH=On \
   -C ${LLVM_SRCDIR}/clang/cmake/caches/Fuchsia-stage2.cmake \
+  -C ${TFLITE_PATH}/tflite.cmake \
   ${LLVM_SRCDIR}/llvm
 
 ninja distribution