Linker error: shared-memory is disallowed

But I don't seem to ask for `--shared-memory`

```
2021-09-16T20:42:51.6704059Z em++ -Wl,--unresolved-symbols=ignore-all -export-dynamic -Wl,-error-limit=0 -s SUPPORT_LONGJMP=1 -s TOTAL_MEMORY=536870912 -s EXIT_RUNTIME=0 -s INVOKE_RUN=0 -s ASSERTIONS=1 -s ERROR_ON_UNDEFINED_SYMBOLS=0 -s FORCE_FILESYSTEM=1 -s LZ4=1 -s MODULARIZE=1 -s EXPORT_NAME=busytex -s EXPORTED_FUNCTIONS='["_main", "_flush_streams"]' -sDEFAULT_LIBRARY_FUNCS_TO_INCLUDE=__sys_statfs64 -s EXPORTED_RUNTIME_METHODS='["callMain", "FS", "ENV", "LZ4", "PATH"]' -o build/wasm/busytex.js build/wasm/busytex.o build/wasm/texlive/texk/web2c/synctexdir/xetex-synctex.o build/wasm/texlive/texk/web2c/xetex-xetexini.o build/wasm/texlive/texk/web2c/xetex-xetex0.o build/wasm/texlive/texk/web2c/xetex-xetex-pool.o build/wasm/texlive/texk/web2c/xetexdir/xetex-xetexextra.o build/wasm/texlive/texk/web2c/lib/lib.a build/wasm/texlive/texk/web2c/libmd5.a build/wasm/texlive/texk/web2c/busytex_libxetex.a build/wasm/texlive/texk/web2c/synctexdir/pdftex-synctex.o build/wasm/texlive/texk/web2c/pdftex-pdftexini.o build/wasm/texlive/texk/web2c/pdftex-pdftex0.o build/wasm/texlive/texk/web2c/pdftex-pdftex-pool.o build/wasm/texlive/texk/web2c/pdftexdir/pdftex-pdftexextra.o build/wasm/texlive/texk/web2c/lib/lib.a build/wasm/texlive/texk/web2c/libmd5.a build/wasm/texlive/texk/web2c/busytex_libpdftex.a build/wasm/texlive/texk/web2c/luatexdir/luatex-luatex.o build/wasm/texlive/texk/web2c/mplibdir/luatex-lmplib.o build/wasm/texlive/texk/web2c/libluatex.a build/wasm/texlive/texk/web2c/libluatexspecific.a build/wasm/texlive/texk/web2c/libluatex.a build/wasm/texlive/texk/web2c/libff.a build/wasm/texlive/texk/web2c/libluamisc.a build/wasm/texlive/texk/web2c/libluasocket.a build/wasm/texlive/texk/web2c/libluaffi.a build/wasm/texlive/texk/web2c/libmplibcore.a build/wasm/texlive/texk/web2c/libmputil.a build/wasm/texlive/texk/web2c/libunilib.a build/wasm/texlive/texk/web2c/libmd5.a build/wasm/texlive/texk/web2c/lib/lib.a build/wasm/texlive/texk/bibtex-x/busytex_bibtex8.a build/wasm/texlive/texk/dvipdfm-x/busytex_xdvipdfmx.a build/wasm/texlive/libs/harfbuzz/libharfbuzz.a build/wasm/texlive/libs/graphite2/libgraphite2.a build/wasm/texlive/libs/teckit/libTECkit.a build/wasm/texlive/libs/libpng/libpng.a build/wasm/fontconfig/src/.libs/libfontconfig.a build/wasm/texlive/libs/freetype2/libfreetype.a build/wasm/texlive/libs/pplib/libpplib.a build/wasm/texlive/libs/zlib/libz.a build/wasm/texlive/libs/zziplib/libzzip.a build/wasm/texlive/libs/libpaper/libpaper.a build/wasm/texlive/libs/icu/icu-build/lib/libicuuc.a build/wasm/texlive/libs/icu/icu-build/lib/libicudata.a build/wasm/texlive/libs/lua53/.libs/libtexlua53.a build/wasm/texlive/libs/xpdf/libxpdf.a build/wasm/texlive/texk/kpathsea/.libs/libkpathsea.a build/wasm/expat/libexpat.a build/wasm/texlive/texk/makeindexk/busytex_makeindex.a -Ibuild/wasm/texlive/libs/icu/include -Ibuild/wasm/fontconfig build/wasm/texlive/texk/kpathsea/busytex_kpsewhich.o build/wasm/texlive/texk/kpathsea/busytex_kpsestat.o build/wasm/texlive/texk/kpathsea/busytex_kpseaccess.o build/wasm/texlive/texk/kpathsea/busytex_kpsereadlink.o build/wasm/texlive/texk/kpathsea/.libs/libkpathsea.a -ldl -lm -pthread
2021-09-16T20:42:52.8961455Z wasm-ld: error: --shared-memory is disallowed by libxetex_a-XeTeXFontInst.o because it was not compiled with 'atomics' or 'bulk-memory' features.
```