Mark as BROKEN on riscv64:
/nxb-bin/usr/lib/clang/11.0.0/include/mmintrin.h:33:5: error: use of undeclared identifier '__builtin_ia32_emms'; did you mean '__builtin_isless'?
Approved by: portmgr (tier-2 blanket)
Obtained from: lonesome.com build testing