Implemented skip_deserializing for enum

serde_codegen/src/de.rs

@@ -496,6 +496,7 @@ fn deserialize_item_enum(
 
     let variant_visitor = deserialize_field_visitor(
         variants.iter()
+            .filter(|variant| !variant.attrs.skip_deserializing())
             .map(|variant| variant.attrs.name().deserialize_name())
             .collect(),
         item_attrs,
@@ -518,7 +519,7 @@ fn deserialize_item_enum(
 
     // Match arms to extract a variant from a string
     let mut variant_arms = vec![];
-    for (i, variant) in variants.iter().enumerate() {
+    for (i, variant) in variants.iter().filter(|variant| !variant.attrs.skip_deserializing()).enumerate() {
         let variant_name = aster::id(format!("__field{}", i));
         let variant_name = quote!(__Field::#variant_name);