Wow, that is very easy to miss. Then I went and looked at Copper and it's a significant piece of work by itself. It's self-hosted (written in Copper), and has LLVM, x86, and x64 backends, and is portable to multiple OSes.

    ~/src/languages/copper-4.5/src$ wc -l *.co */*.co
      5296 builder.co
      1002 commons.co
       604 lexer.co
       191 main.co
      2067 parser.co
      2437 codegen/generator-c.co
       508 codegen/generator-dump.co
      2388 codegen/generator-llvm.co
      8896 codegen/generator-x64.co
      9617 codegen/generator-x86.co
       534 data/ast.co
      1466 data/object-file-coff.co
      1185 data/object-file-elf64.co
      1367 data/object-file-elf.co
      5538 data/program.co
       461 data/token.co
     43557 total