Parse super let syntax (#1889)

Author: AMDmi3

src/gen/clone.rs

@@ -42,6 +42,7 @@ ast_struct! {
     #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
     pub struct Local {
         pub attrs: Vec<Attribute>,
+        pub super_token: Option<Token![super]>,
         pub let_token: Token![let],
         pub pat: Pat,
         pub init: Option<LocalInit>,
@@ -217,7 +218,9 @@ pub(crate) mod parsing {
             }
         }
 
-        if input.peek(Token![let]) && !input.peek(token::Group) {
+        if (input.peek(Token![let]) || input.peek(Token![super]) && input.peek2(Token![let]))
+            && !input.peek(token::Group)
+        {
             stmt_local(input, attrs).map(Stmt::Local)
         } else if input.peek(Token![pub])
             || input.peek(Token![crate]) && !input.peek2(Token![::])
@@ -281,6 +284,12 @@ pub(crate) mod parsing {
     }
 
     fn stmt_local(input: ParseStream, attrs: Vec<Attribute>) -> Result<Local> {
+        let super_token: Option<Token![super]> = if input.peek(Token![super]) {
+            Some(input.parse()?)
+        } else {
+            None
+        };
+
         let let_token: Token![let] = input.parse()?;
 
         let mut pat = Pat::parse_single(input)?;
@@ -324,6 +333,7 @@ pub(crate) mod parsing {
 
         Ok(Local {
             attrs,
+            super_token,
             let_token,
             pat,
             init,
@@ -449,6 +459,9 @@ pub(crate) mod printing {
     impl ToTokens for Local {
         fn to_tokens(&self, tokens: &mut TokenStream) {
             expr::printing::outer_attrs_to_tokens(&self.attrs, tokens);
+            if let Some(super_token) = &self.super_token {
+                super_token.to_tokens(tokens);
+            }
             self.let_token.to_tokens(tokens);
             self.pat.to_tokens(tokens);
             if let Some(init) = &self.init {

src/gen/fold.rs

@@ -237,10 +237,6 @@ static EXCLUDE_FILES: &[&str] = &[
     // https://github.com/dtolnay/syn/issues/1705
     "src/tools/rustfmt/tests/target/cfg_attribute_in_where.rs",
 
-    // TODO: super let
-    // https://github.com/dtolnay/syn/issues/1889
-    "src/tools/rust-analyzer/crates/parser/test_data/parser/inline/ok/let_stmt.rs",
-
     // TODO: "ergonomic clones": `f(obj.use)`, `thread::spawn(use || f(obj))`, `async use`
     // https://github.com/dtolnay/syn/issues/1802
     "tests/codegen-llvm/ergonomic-clones/closure.rs",