[teamhimeh]

Problem

JNI extraction treats an immutable actor property as asynchronous when its protocol inherits AnyObject or Sendable, including their Swift.-qualified spellings. These standard constraints introduce no actor isolation, but are absent from SwiftExtract's built-in Swift symbol table, so the synchronous protocol-witness check rejects them.

For example:

public protocol Identified: AnyObject, Sendable {
  var identifier: Int64 { get }
}

public actor Record: Identified {
  public let identifier: Int64

  public init(identifier: Int64) {
    self.identifier = identifier
  }
}

Previously, the generated actor getter returned CompletableFuture<Long>. With this change, Java callers can read the synchronous witness directly:

try (var arena = SwiftArena.ofConfined()) {
    Record record = Record.init(42, arena);
    long identifier = record.getIdentifier(); // 42
}

The Swift thunk continues to read (record as any Identified).identifier, preserving synchronous access across module boundaries.

Changes

• Recognize AnyObject, Swift.AnyObject, Sendable, and Swift.Sendable as nonisolating standard constraints during actor-property witness discovery.
• Apply this exception only when lookup is unresolved or resolves to the Swift module. Locally declared protocols named Sendable retain their actual isolation checks.
• Cover each spelling, combined and inherited constraints, and an actor-isolated local Sendable in extraction regressions. Check both synchronous Java signatures and protocol-based Swift downcalls in generator regressions.
• Add a JNI sample actor whose protocol inherits both constraints and a Java runtime test that reads its getter as a long.

Validation

• Confirmed the positive extraction and generator regressions fail before the fix and pass afterward; the local Sendable isolation regression passes before and after.
• swift test --disable-experimental-prebuilts --disable-sandbox --jobs 4: full Swift test suite passed. One existing test requiring Android API 34/35 platform data was skipped.
• ./gradlew :Samples:SwiftJavaExtractJNISampleApp:test --no-daemon: all 296 Java tests passed with no failures or skips, including the new synchronous actor getter test.
• Compiled a separate two-module Swift 6 example: the protocol-witness read succeeds, while direct synchronous access to the actor's stored property fails with the expected isolation diagnostic. All five standard-constraint spellings used by the regressions also typecheck in Swift 6.
• swift-format lint --strict on changed Swift files and git diff --check passed.

Tested with Apple Swift 6.4 and JetBrains Runtime 25.0.2 on macOS.

Dependency

This follows #4. The base branch already contains actor-property witness discovery and protocol-based thunk dispatch; this diff extends the handling of inherited standard constraints.