Original 16bit x86 was 8080/8085 assembly upgrade to 16bit (source code compatible to the 8080), and the Z80 was a upgraded clone for the 8080. You can get a as

Original 16bit x86 was 8080/8085 assembly upgrade to 16bit (source code compatible to the 8080), and the Z80 was a upgraded clone for the 8080. You can get a assembly code for a 8080 and just compile it for the 8086 and it would work. So, it's logic that compilers that target Z80/8080/8085, generate something similar to what any compiler would do on x86.