Add windres wrapper for LLVM tools

Dockerfile

@@ -23,12 +23,6 @@ COPY *.sh libssp-Makefile ./
 COPY wrappers/*.sh ./wrappers/
 RUN ./build-all.sh $TOOLCHAIN_PREFIX && \
     ./strip-llvm.sh $TOOLCHAIN_PREFIX && \
-    apt-get update -qq && \
-    apt-get install -qqy binutils-mingw-w64-x86-64 && \
-    cp /usr/bin/x86_64-w64-mingw32-windres $TOOLCHAIN_PREFIX/bin/x86_64-w64-mingw32-windresreal && \
-    apt-get remove -qqy binutils-mingw-w64-x86-64 && \
-    apt-get clean -y && \
-    rm -rf /var/lib/apt/lists/* && \
     rm -rf /build
 
 ENV PATH=$TOOLCHAIN_PREFIX/bin:$PATH