message: engine-universal: fix compilation with default features off
diff: @@ -164,6 +164,7 @@ pub struct UniversalEngineInner {
  impl UniversalEngineInner {
  /// Gets the compiler associated to this engine.
  + #[cfg(feature = "compiler")]
  pub fn compiler(&self) -> Result<&dyn Compiler, CompileError> {
  self.builder.compiler()
  }
  