Set -fno-commom flag to avoid ASan global issues.

Author: robertbartel

.github/actions/ngen-build/action.yaml

@@ -199,8 +199,8 @@ runs:
             if [ ${{ runner.os }} == 'macOS' ]
             then
               echo "fun:PyType_FromMetaclass" > /tmp/asan_ignore.txt
-              export CFLAGS="$CFLAGS -fsanitize-ignorelist=/tmp/asan_ignore.txt"
-              export CXXFLAGS="$CXXFLAGS -fsanitize-ignorelist=/tmp/asan_ignore.txt"
+              export CFLAGS="$CFLAGS -fsanitize-ignorelist=/tmp/asan_ignore.txt -fno-common"
+              export CXXFLAGS="$CXXFLAGS -fsanitize-ignorelist=/tmp/asan_ignore.txt -fno-common"
             fi
             . .venv/bin/activate
             [ ! -d "$BOOST_ROOT" ] && echo "Error: no Boost root found at $BOOST_ROOT" && exit 1