[SE-0458] Always parse "unsafe" expressions and for..in effects

Author: DougGregor

Sources/SwiftParser/TokenSpecSet.swift

@@ -714,7 +714,7 @@ enum ExpressionModifierKeyword: TokenSpecSet {
     case TokenSpec(.repeat): self = .repeat
     case TokenSpec(.each): self = .each
     case TokenSpec(.any): self = .any
-    case TokenSpec(.unsafe) where experimentalFeatures.contains(.unsafeExpression): self = .unsafe
+    case TokenSpec(.unsafe): self = .unsafe
     default: return nil
     }
   }

Tests/SwiftParserTest/ExpressionTests.swift

@@ -2194,8 +2194,7 @@ final class StatementExpressionTests: ParserTestCase {
       func f() {
         let x = unsafe y
       }
-      """,
-      experimentalFeatures: .unsafeExpression
+      """
     )
 
     assertParse(

Tests/SwiftParserTest/StatementTests.swift

@@ -960,23 +960,19 @@ final class StatementTests: ParserTestCase {
 
   func testForUnsafeStatement() {
     assertParse(
-      "for try await unsafe x in e { }",
-      experimentalFeatures: [.unsafeExpression]
+      "for try await unsafe x in e { }"
     )
 
     assertParse(
-      "for try await unsafe in e { }",
-      experimentalFeatures: [.unsafeExpression]
+      "for try await unsafe in e { }"
     )
 
     assertParse(
-      "for unsafe in e { }",
-      experimentalFeatures: [.unsafeExpression]
+      "for unsafe in e { }"
     )
 
     assertParse(
-      "for unsafe: Int in e { }",
-      experimentalFeatures: [.unsafeExpression]
+      "for unsafe: Int in e { }"
     )
   }
 }