message: Add wasmer_runtime_core::backend::Compiler to compatibility wrapper
diff: use crate::new;
  -pub use new::wasmer_compiler::{Architecture, CpuFeature as Features};
  +pub use new::wasmer_compiler::{Architecture, Compiler, CpuFeature as Features};
  /// Enum used to select which compiler should be used to generate code.
  #[derive(Debug, Copy, Clone, PartialEq, Eq)]
  