Revert "[DirectoryWatcher] Use RetryAfterSignal"
Revert "[DirectoryWatcher] Use RetryAfterSignal"

This reverts commit 647c601471637f25e85a6c2bed5f8954079fd6a9.

apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang