feat: pass_by_value lint attribute

Useful for thin wrapper attributes that are best passed as value instead
of reference.

compiler/rustc_span/src/symbol.rs

@@ -1143,6 +1143,7 @@ symbols! {
         rustc_paren_sugar,
         rustc_partition_codegened,
         rustc_partition_reused,
+        rustc_pass_by_value,
         rustc_peek,
         rustc_peek_definite_init,
         rustc_peek_liveness,