remove libxml2 dependency

closes #9
closes #7

Dockerfile

@@ -18,25 +18,13 @@ RUN apk update && \
 RUN mkdir -p /deps
 ARG MAKE_JOBS=-j1
 
-# xml2
-WORKDIR /deps
-RUN wget ftp://ftp.xmlsoft.org/libxml2/libxml2-2.9.7.tar.gz
-RUN tar xf libxml2-2.9.7.tar.gz
-WORKDIR /deps/libxml2-2.9.7
-RUN autoreconf
-RUN ./configure --without-python --disable-shared --prefix=/deps/local
-RUN make $MAKE_JOBS install
-
 # llvm
 WORKDIR /deps
 RUN wget http://releases.llvm.org/7.0.0/llvm-7.0.0.src.tar.xz
 RUN tar xf llvm-7.0.0.src.tar.xz
-WORKDIR /deps/llvm-7.0.0.src/
-COPY llvm-fix-libxml2-dep.patch ./
-RUN patch -p0 -i llvm-fix-libxml2-dep.patch
 RUN mkdir -p /deps/llvm-7.0.0.src/build
 WORKDIR /deps/llvm-7.0.0.src/build
-RUN cmake .. -DCMAKE_INSTALL_PREFIX=/deps/local -DCMAKE_PREFIX_PATH=/deps/local -DCMAKE_BUILD_TYPE=Release -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD="WebAssembly;AVR;RISCV"
+RUN cmake .. -DCMAKE_INSTALL_PREFIX=/deps/local -DCMAKE_PREFIX_PATH=/deps/local -DCMAKE_BUILD_TYPE=Release -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD="WebAssembly;AVR;RISCV" -DLLVM_ENABLE_LIBXML2=OFF
 RUN make $MAKE_JOBS install
 
 # clang