Make @abi non-experimental

CodeGeneration/Sources/SyntaxSupport/AttributeNodes.swift

@@ -122,8 +122,7 @@ public let ATTRIBUTE_NODES: [Node] = [
           Child(
             name: "abiArguments",
             // Special arguments for declaration syntax. e.g. @abi(func abiName() -> Int)
-            kind: .node(kind: .abiAttributeArguments),
-            experimentalFeature: .abiAttribute
+            kind: .node(kind: .abiAttributeArguments)
           ),
         ]),
         documentation: """
@@ -256,7 +255,6 @@ public let ATTRIBUTE_NODES: [Node] = [
   Node(
     kind: .abiAttributeArguments,
     base: .syntax,
-    experimentalFeature: .abiAttribute,
     nameForDiagnostics: "ABI-providing declaration",
     documentation: "The arguments of the '@abi' attribute",
     children: [

CodeGeneration/Sources/SyntaxSupport/ExperimentalFeatures.swift

@@ -19,7 +19,6 @@ public enum ExperimentalFeature: String, CaseIterable {
   case nonescapableTypes
   case trailingComma
   case coroutineAccessors
-  case abiAttribute
   case keypathWithMethodMembers
   case oldOwnershipOperatorSpellings
   case inlineArrayTypeSugar
@@ -39,8 +38,6 @@ public enum ExperimentalFeature: String, CaseIterable {
       return "TrailingComma"
     case .coroutineAccessors:
       return "CoroutineAccessors"
-    case .abiAttribute:
-      return "ABIAttribute"
     case .keypathWithMethodMembers:
       return "KeypathWithMethodMembers"
     case .oldOwnershipOperatorSpellings:
@@ -65,8 +62,6 @@ public enum ExperimentalFeature: String, CaseIterable {
       return "trailing commas"
     case .coroutineAccessors:
       return "coroutine accessors"
-    case .abiAttribute:
-      return "@abi attribute"
     case .keypathWithMethodMembers:
       return "keypaths with method members"
     case .oldOwnershipOperatorSpellings:

CodeGeneration/Sources/SyntaxSupport/KeywordSpec.swift

@@ -357,7 +357,7 @@ public enum Keyword: CaseIterable {
     case ._version:
       return KeywordSpec("_version")
     case .abi:
-      return KeywordSpec("abi", experimentalFeature: .abiAttribute)
+      return KeywordSpec("abi")
     case .accesses:
       return KeywordSpec("accesses")
     case .actor:

Sources/SwiftParser/Attributes.swift

@@ -230,9 +230,9 @@ extension Parser {
     switch peek(isAtAnyIn: DeclarationAttributeWithSpecialSyntax.self) {
     case .abi:
       return parseAttribute(argumentMode: .required) { parser in
-        return parser.parseABIAttributeArguments()
+        return (nil, .abiArguments(parser.parseABIAttributeArguments()))
       } parseMissingArguments: { parser in
-        return parser.parseABIAttributeArguments(missingLParen: true)
+        return (nil, .abiArguments(parser.parseABIAttributeArguments(missingLParen: true)))
       }
     case .available, ._spi_available:
       return parseAttribute(argumentMode: .required) { parser in
@@ -794,9 +794,9 @@ extension Parser {
   /// - Parameter missingLParen: `true` if the opening paren for the argument list was missing.
   mutating func parseABIAttributeArguments(
     missingLParen: Bool = false
-  ) -> (RawUnexpectedNodesSyntax?, RawAttributeSyntax.Arguments) {
-    func makeMissingProviderArguments(unexpectedBefore: [RawSyntax]) -> RawAttributeSyntax.Arguments {
-      let args = RawABIAttributeArgumentsSyntax(
+  ) -> RawABIAttributeArgumentsSyntax {
+    func makeMissingProviderArguments(unexpectedBefore: [RawSyntax]) -> RawABIAttributeArgumentsSyntax {
+      return RawABIAttributeArgumentsSyntax(
         provider: .missing(
           RawMissingDeclSyntax(
             unexpectedBefore.isEmpty ? nil : RawUnexpectedNodesSyntax(elements: unexpectedBefore, arena: self.arena),
@@ -808,7 +808,6 @@ extension Parser {
         ),
         arena: self.arena
       )
-      return .abiArguments(args)
     }
 
     // Consider the three kinds of mistakes we might see here:
@@ -824,23 +823,16 @@ extension Parser {
     // In lieu of that, we judge that recovering gracefully from #3 is more important than #2 and therefore do not even
     // attempt to parse the argument unless we've seen a left paren.
     guard !missingLParen && !self.at(.rightParen) else {
-      return (nil, makeMissingProviderArguments(unexpectedBefore: []))
+      return makeMissingProviderArguments(unexpectedBefore: [])
     }
 
     let decl = parseDeclaration(in: .argumentList)
 
-    guard experimentalFeatures.contains(.abiAttribute) else {
-      return (
-        RawUnexpectedNodesSyntax([decl], arena: self.arena),
-        .argumentList(RawLabeledExprListSyntax(elements: [], arena: self.arena))
-      )
-    }
-
     guard let provider = RawABIAttributeArgumentsSyntax.Provider(decl) else {
-      return (nil, makeMissingProviderArguments(unexpectedBefore: [decl.raw]))
+      return makeMissingProviderArguments(unexpectedBefore: [decl.raw])
     }
 
-    return (nil, .abiArguments(RawABIAttributeArgumentsSyntax(provider: provider, arena: self.arena)))
+    return RawABIAttributeArgumentsSyntax(provider: provider, arena: self.arena)
   }
 }