message: Fix lint errors when singlepass is disabled.
diff: @@ -860,9 +860,15 @@ fn validate(validate: Validate) {
  }
  }
  -fn get_compiler_by_backend(backend: Backend, opts: &Run) -> Option<Box<dyn Compiler>> {
  +fn get_compiler_by_backend(backend: Backend, _opts: &Run) -> Option<Box<dyn Compiler>> {
  + Some(match backend {
  + #[cfg(feature = "backend-singlepass")]
  + Backend::Singlepass => {
  + use wasmer_runtime_core::codegen::StreamingCompiler;
  + use wasmer_singlepass_backend::ModuleCodeGenerator as SinglePassMCG;
  use wasmer_runtime_core::codegen::MiddlewareChain;
  - let opts = opts.clone();
  +
  + let opts = _opts.clone();
  let middlewares_gen = move || {
  let mut middlewares = MiddlewareChain::new();
  if opts.call_trace {
  @@ -876,12 +882,6 @@ fn get_compiler_by_backend(backend: Backend, opts: &Run) -> Option<Box<dyn Compi
  middlewares
  };
  - Some(match backend {
  - #[cfg(feature = "backend-singlepass")]
  - Backend::Singlepass => {
  - use wasmer_runtime_core::codegen::StreamingCompiler;
  - use wasmer_singlepass_backend::ModuleCodeGenerator as SinglePassMCG;
  -
  let c: StreamingCompiler<SinglePassMCG, _, _, _, _> =
  StreamingCompiler::new(middlewares_gen);
  Box::new(c)
  