message: change func_index offset by number of imported funcs
diff: @@ -530,7 +530,10 @@ impl<'module, 'isa, 'data> ModuleEnvironment<'data> for ModuleEnv<'module, 'isa>
  .special_param(ir::ArgumentPurpose::VMContext)
  .expect("missing vmctx parameter");
  - let func_index = pos.ins().iconst(ir::types::I32, func_index.index() as i64);
  + let func_index = pos.ins().iconst(
  + ir::types::I32,
  + func_index.index() as i64 + self.module.info.imported_functions.len() as i64,
  + );
  pos.ins().call(start_debug, &[vmctx, func_index]);
  