Mike Pall somewhat famously wrote a Lua interpreter in assembler. Assuming that you can write a compiler for your language in Lua, you don't really have to trust trust, but you do have to trust Mike Pall. I'm not aware of any other raw assembly implementations of modern programming languages, but I suspect there are other examples. The overall scheme (^,~) could probably be replicated by a sufficiently dedicated team if there was interest.
Not exactly easy, but probably easier than a decompiler that produces human-equivalent source code.
Not exactly easy, but probably easier than a decompiler that produces human-equivalent source code.