Add tests for attributes not in meta-item form

Author: ninevra

corpus/declarations.txt

@@ -812,6 +812,91 @@ mod macos_only {
           (identifier)
           value: (string_literal))))))))
 
+============================================
+Attribute macros
+============================================
+
+foo(#[attr(=> arbitrary tokens <=)] x, y);
+
+foo(#[bar(some tokens are special in other contexts: $/';()*()+.)] x);
+
+---
+
+(source_file
+  (call_expression
+    function: (identifier)
+    arguments: (arguments
+      (attribute_item (attr_item
+        (identifier)
+        arguments: (delim_token_tree (identifier) (identifier))))
+      (identifier)
+      (identifier)))
+  (call_expression
+    function: (identifier)
+    arguments: (arguments
+      (attribute_item (attr_item
+        (identifier)
+        arguments: (delim_token_tree
+          (identifier)
+          (identifier)
+          (identifier)
+          (identifier)
+          (identifier)
+          (identifier)
+          (identifier)
+          (delim_token_tree)
+          (delim_token_tree))))
+      (identifier))))
+
+============================================
+Derive macro helper attributes
+============================================
+
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum Error {
+    #[error("first letter must be lowercase but was {:?}", first_char(.0))]
+    WrongCase(String),
+    #[error("invalid index {idx}, expected at least {} and at most {}", .limits.lo, .limits.hi)]
+    OutOfBounds { idx: usize, limits: Limits },
+}
+
+---
+
+(source_file
+  (use_declaration
+    (scoped_identifier (identifier) (identifier)))
+  (attribute_item
+    (meta_item (identifier)
+      (meta_arguments
+        (meta_item (identifier))
+        (meta_item (identifier)))))
+  (enum_item
+    (visibility_modifier)
+    (type_identifier)
+    (enum_variant_list
+      (attribute_item (attr_item
+        (identifier)
+        (delim_token_tree
+          (string_literal)
+          (identifier)
+          (delim_token_tree (integer_literal)))))
+      (enum_variant (identifier)
+        (ordered_field_declaration_list (type_identifier)))
+      (attribute_item (attr_item
+        (identifier)
+        (delim_token_tree
+          (string_literal)
+          (identifier)
+          (identifier)
+          (identifier)
+          (identifier))))
+      (enum_variant (identifier)
+        (field_declaration_list
+          (field_declaration (field_identifier) (primitive_type))
+          (field_declaration (field_identifier) (type_identifier)))))))
+
 ============================================
 Attributes and Expressions
 ============================================