perf(atoms): Remove temporary allocations in rkyv serialize and deserialize (#11202)

**Description:**

Remove temporary allocations under serialize and deserialize.

Author: h-a-n-a

crates/swc_atoms/src/lib.rs

@@ -262,7 +262,7 @@ where
     <S as rancor::Fallible>::Error: rancor::Source,
 {
     fn serialize(&self, serializer: &mut S) -> Result<Self::Resolver, S::Error> {
-        String::serialize(&self.to_string(), serializer)
+        rkyv::string::ArchivedString::serialize_from_str(self.as_str(), serializer)
     }
 }
 
@@ -272,10 +272,8 @@ impl<D> rkyv::Deserialize<Atom, D> for rkyv::string::ArchivedString
 where
     D: ?Sized + rancor::Fallible,
 {
-    fn deserialize(&self, deserializer: &mut D) -> Result<Atom, <D as rancor::Fallible>::Error> {
-        let s: String = self.deserialize(deserializer)?;
-
-        Ok(Atom::new(s))
+    fn deserialize(&self, _: &mut D) -> Result<Atom, <D as rancor::Fallible>::Error> {
+        Ok(Atom::new(self.as_str()))
     }
 }
 

crates/swc_atoms/src/wtf8_atom.rs

@@ -197,16 +197,11 @@ where
     D: ?Sized + rancor::Fallible,
     <D as rancor::Fallible>::Error: rancor::Source,
 {
-    fn deserialize(
-        &self,
-        deserializer: &mut D,
-    ) -> Result<Wtf8Atom, <D as rancor::Fallible>::Error> {
-        let s: Vec<u8> = self.deserialize(deserializer)?;
-
+    fn deserialize(&self, _: &mut D) -> Result<Wtf8Atom, <D as rancor::Fallible>::Error> {
         Ok(Wtf8Atom::new(
             // SAFETY: `ArchivedVec<u8>` is guaranteed to be serialized with `Wtf8Atom` byte
             // sequence.  `Wtf8Atom` byte sequence is identical to `Wtf8` byte sequence.
-            unsafe { Wtf8::from_bytes_unchecked(&s) },
+            unsafe { Wtf8::from_bytes_unchecked(self.as_slice()) },
         ))
     }
 }