Add @_staticExclusiveOnly to Atomic

Author: Azoy

stdlib/public/Synchronization/Atomic.swift

@@ -14,8 +14,9 @@ import Builtin
 
 /// An atomic value.
 @available(SwiftStdlib 5.11, *)
-@_rawLayout(like: Value.AtomicRepresentation)
 @frozen
+@_rawLayout(like: Value.AtomicRepresentation)
+@_staticExclusiveOnly
 public struct Atomic<Value: AtomicValue>: ~Copyable {
   @available(SwiftStdlib 5.11, *)
   @_alwaysEmitIntoClient

stdlib/public/Synchronization/AtomicLazyReference.swift

@@ -16,6 +16,7 @@
 /// times.
 @available(SwiftStdlib 5.11, *)
 @frozen
+@_staticExclusiveOnly
 public struct AtomicLazyReference<Instance: AnyObject>: ~Copyable {
   @usableFromInline
   let storage: Atomic<Unmanaged<Instance>?>

stdlib/public/Synchronization/CMakeLists.txt

@@ -30,6 +30,7 @@ add_swift_target_library(swiftSynchronization ${SWIFT_STDLIB_LIBRARY_BUILD_TYPES
     ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
     "-enable-builtin-module"
     "-enable-experimental-feature" "RawLayout"
+    "-enable-experimental-feature" "StaticExclusiveOnly"
 
   INSTALL_IN_COMPONENT
     stdlib