enh(swift) `@unchecked` and `@Sendable` support (#3808)

* @Sendable is a keyword attribute

* Add @unchecked for Sendable conformance

* Use scope spelling for attribute rules

* @unchecked is not actually contextual

* Revert unneeded changes

* Update CHANGES.md

CHANGES.md

@@ -14,6 +14,7 @@ Core Grammars:
 - enh(swift) support `macro` keyword [Bradley Mackey][]
 - enh(swift) support parameter pack keywords [Bradley Mackey][]
 - enh(swift) regex literal support [Bradley Mackey][]
+- enh(swift) `@unchecked` and `@Sendable` support [Bradley Mackey][]
 
 Dev tool: 
 

src/languages/lib/kws_swift.js

@@ -305,8 +305,10 @@ export const keywordAttributes = [
   'propertyWrapper',
   'requires_stored_property_inits',
   'resultBuilder',
+  'Sendable',
   'testable',
   'UIApplicationMain',
+  'unchecked',
   'unknown',
   'usableFromInline'
 ];

src/languages/swift.js

@@ -243,7 +243,7 @@ export default function(hljs) {
   // https://docs.swift.org/swift-book/ReferenceManual/Attributes.html
   const AVAILABLE_ATTRIBUTE = {
     match: /(@|#(un)?)available/,
-    className: "keyword",
+    scope: 'keyword',
     starts: { contains: [
       {
         begin: /\(/,
@@ -258,11 +258,11 @@ export default function(hljs) {
     ] }
   };
   const KEYWORD_ATTRIBUTE = {
-    className: 'keyword',
+    scope: 'keyword',
     match: concat(/@/, either(...Swift.keywordAttributes))
   };
   const USER_DEFINED_ATTRIBUTE = {
-    className: 'meta',
+    scope: 'meta',
     match: concat(/@/, Swift.identifier)
   };
   const ATTRIBUTES = [

test/markup/swift/attributes.expect.txt

@@ -5,5 +5,7 @@
 <span class="hljs-keyword">@propertyWrapper</span>
 <span class="hljs-meta">@SomeWrapper</span>(value: <span class="hljs-number">1.0</span>, other: <span class="hljs-string">&quot;string&quot;</span>, bool: <span class="hljs-literal">false</span>)
 <span class="hljs-keyword">@resultBuilder</span>
+<span class="hljs-keyword">@Sendable</span>
+<span class="hljs-keyword">@unchecked</span>
 
 @ notAnAttribute

test/markup/swift/attributes.txt

@@ -5,5 +5,7 @@
 @propertyWrapper
 @SomeWrapper(value: 1.0, other: "string", bool: false)
 @resultBuilder
+@Sendable
+@unchecked
 
 @ notAnAttribute