i32 (ptr): A call to built-in function 'memcpy' is not supported.

[vincentmli]

custom_memcpy in https://github.com/vincentmli/xdp-tools/blob/master/xdp-dns/xdp_dns.bpf.c compiles fine but custom_memcpy in https://github.com/vincentmli/xdp-tools/blob/bpf-dnyptr/xdp-dns/xdp_dns.bpf.c result in compiler error i32 (ptr): A call to built-in function 'memcpy' is not supported, switch custom_memcpy to __builtin_memcpy has same compiler error

[vincentmli]

Hi @yonghong-song, Vincent here :) when you have time, could you help looking at above code example why I got the clang compiler error with custom_memcpy, I am not sure if following is related

llvm/llvm-project#93700
llvm/llvm-project#97648