Revert "Add a lint for the Self tuple struct soundness hole" (#319)

Author: thomcc

doc/src/config-lints.md

@@ -264,26 +264,3 @@ foo::<dyn SomeTrait>();
 // Trait object in type default (enum, union, trait, and so on are all also forbidden)
 struct SomeStruct<T = dyn SomeTrait>(...);
 ```
-
-### `plrust_tuple_struct_self_pattern`
-
-This lint forbids use of a tuple struct named `Self` in pattern position. This
-can be used to bypass struct field privacy prior to Rust 1.71.0
-(<https://github.com/rust-lang/rust/issues/111220>). Once PL/Rust depends on
-1.71.0, this lint will be replaced by one that does nothing, as the offending
-pattern will not compile.
-
-For example, this lint will prevent the following code:
-
-```rs
-mod my {
-    pub struct Foo(&'static str);
-}
-
-impl AsRef<str> for my::Foo {
-    fn as_ref(&self) -> &str {
-        let Self(s) = self;
-        s
-    }
-}
-```

plrust/src/lib.rs

@@ -95,7 +95,6 @@ const DEFAULT_LINTS: &'static str = "\
     plrust_print_macros, \
     plrust_stdio, \
     plrust_suspicious_trait_object, \
-    plrust_tuple_struct_self_pattern, \
     unsafe_code, \
     deprecated, \
     suspicious_auto_trait_impls, \

plrustc/plrustc/src/lints/mod.rs

@@ -19,7 +19,6 @@ mod print_macros;
 mod static_impls;
 mod stdio;
 mod sus_trait_object;
-mod tuple_struct_self_pattern;
 
 static INCLUDE_TEST_ONLY_LINTS: Lazy<bool> =
     Lazy::new(|| std::env::var("PLRUSTC_INCLUDE_TEST_ONLY_LINTS").is_ok());
@@ -39,7 +38,6 @@ static PLRUST_LINTS: Lazy<Vec<&'static Lint>> = Lazy::new(|| {
         print_macros::PLRUST_PRINT_MACROS,
         stdio::PLRUST_STDIO,
         sus_trait_object::PLRUST_SUSPICIOUS_TRAIT_OBJECT,
-        tuple_struct_self_pattern::PLRUST_TUPLE_STRUCT_SELF_PATTERN,
     ];
     if *INCLUDE_TEST_ONLY_LINTS {
         let test_only_lints = [force_ice::PLRUST_TEST_ONLY_FORCE_ICE];
@@ -85,7 +83,6 @@ pub fn register(store: &mut LintStore, _sess: &Session) {
     store.register_late_pass(move |_| Box::new(stdio::PlrustPrintFunctions));
     store.register_late_pass(move |_| Box::new(extern_blocks::NoExternBlockPass));
     store.register_late_pass(move |_| Box::new(lifetime_param_trait::LifetimeParamTraitPass));
-    store.register_late_pass(move |_| Box::new(tuple_struct_self_pattern::TupleStructSelfPat));
 
     if *INCLUDE_TEST_ONLY_LINTS {
         store.register_early_pass(move || Box::new(force_ice::PlrustcForceIce));

plrustc/plrustc/src/lints/tuple_struct_self_pattern.rs

@@ -7,7 +7,6 @@ extern crate rustc_interface;
 
 extern crate rustc_lint;
 extern crate rustc_lint_defs;
-extern crate rustc_middle;
 extern crate rustc_session;
 extern crate rustc_span;