Has this been done without jumping through hoops like compiling to a specific CPU target with GCC then doing a binary conversion to JVM bytecode (NestedVM does this via MIPS I believe)?
Depends on what you mean by hoops (ala clang), but there is Graal which can run LLVM bitcode [0] but I am unsure if it can compile it. I have personally compiled C code to WASM and then to the JVM via [1]. C/C++ are complex (and/or have complex optimizations) so a compiler should be used, but doesn't necessarily have to target a specific CPU but still have to have a bit-preference and what not. And of course once you interact with the system, some abstraction has to occur somewhere.
GraavlVM Seems like an incredibly useful tool for sandboxing non-java languages with java/jvm interoperability. LLVM really is enabling a renaissance of language interop. This is fantastic stuff.
