Replace the "extern not ported -> bail" stub in Vm.invoke with callHostExtern: resolve the symbol via host_ffi.lookupSymbol (dlsym RTLD_DEFAULT) and dispatch through the host_ffi trampolines, like the legacy interp.callExtern. Marshalling is trivial now that Addr is a real host pointer (4D.0): every WORD-kind arg passes as usize verbatim (a scalar's bits OR a pointer, no translation), and a pointer return is a valid Addr. Picks callPtrRet (void*-ABI) for pointer-ish returns, callIntRet (i64-ABI) otherwise; honors variadic. Non-word (aggregate/string/float) args+returns bail loudly (4D.2 adds them). One general mechanism for all externs, not per-builtin special cases. New example 0636-comptime-extern-libc (#run toupper(97)/tolower(90) -> 65/122) runs HANDLED on the VM, output byte-matching legacy. 698/0 both gates.
2 B
2 B