Physim images: build using clang and -Werror

docker/Dockerfile.phySim.rhel8.2

@@ -31,14 +31,16 @@ RUN rm -Rf /oai-ran
 WORKDIR /oai-ran
 COPY . .
 
-#only install address sanitizer for this container, the others don't need it
-RUN yum install -y libasan
+#only install address sanitizer and LLVM (clang, ...) for this container, the others don't need it
+RUN yum install -y libasan llvm-toolset
 
 #run build_oai to build the target image
 RUN /bin/sh oaienv && \ 
     cd cmake_targets && \
     mkdir -p log && \
-    ./build_oai --phy_simulators --ninja --verbose-ci --sanitize-address --noavx512 -c
+    export CC=/usr/bin/clang && \
+    export CXX=/usr/bin/clang++ && \
+    ./build_oai --phy_simulators --gNB --eNB --nrUE --UE --ninja --verbose-ci --sanitize-address --noavx512 -c --cmake-opt -DCMAKE_C_FLAGS=-Werror --cmake-opt -DCMAKE_CXX_FLAGS=-Werror
 
 #start from scratch for target executable
 FROM registry.access.redhat.com/ubi8/ubi:latest as oai-physim