Adding pocl version of the simpletrack container

lhc/simpletrack/Dockerfile.pocl

+FROM debian:latest
+
+ARG LLVM_VERSION=7
+ENV OCL_ICD_VENDORS=/pocl/build/ocl-vendors
+ENV POCL_BUILDING=1
+
+ENV PARTICLES 20000
+ENV TURNS 15
+ENV DEVICE "0.0"
+
+RUN apt update && apt upgrade -y \
+    && apt-get install -y build-essential ocl-icd-libopencl1 cmake git gcc g++ libhwloc5 pkg-config python3-pip libclang-${LLVM_VERSION}-dev clang-${LLVM_VERSION} llvm-${LLVM_VERSION}-dev make ninja-build ocl-icd-libopencl1 ocl-icd-dev ocl-icd-opencl-dev libhwloc-dev zlib1g zlib1g-dev clinfo
+
+RUN git clone https://github.com/pocl/pocl.git \
+    && cd pocl && mkdir build && cd build && cmake -G Ninja .. \
+    && ninja
+
+RUN mkdir /.cache && chmod -R 777 /.cache/ \
+    && git clone https://github.com/rdemaria/simpletrack.git \
+    && cd simpletrack && pip3 install pyopencl && pip3 install -e . 
+
+ENTRYPOINT [ "/bin/bash", "-c", "cd /simpletrack/examples/lhc/ && python3 benchmark_opencl.py -p $PARTICLES -t $TURNS -d $DEVICE" ]