add -fvisibility=hidden flags

Author: lkeegan

build.sh

@@ -41,6 +41,9 @@ cmake -GNinja .. \
     -DPython3_EXECUTABLE=$PYTHON_EXE \
     -DCMAKE_INSTALL_PREFIX=$INSTALL_PREFIX \
     -DCMAKE_BUILD_TYPE=Release \
+    -DBUILD_SHARED_LIBS=OFF \
+    -DCMAKE_C_FLAGS="-fpic -fvisibility=hidden" \
+    -DCMAKE_CXX_FLAGS="-fpic -fvisibility=hidden" \
     -DLLVM_DEFAULT_TARGET_TRIPLE=$TARGET_TRIPLE \
     -DCMAKE_OSX_DEPLOYMENT_TARGET=$MACOSX_DEPLOYMENT_TARGET \
     -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \