Fix SWIFT_TASK_DEBUG_LOG macro

The threading library changed in the BackDeployConcurrency library
resulting in the `SWIFT_TASK_DEBUG_LOG` macro not compiling. Fixing
that. Also adding the logging pieces to the Compatibility 56 library.

Author: etcwilde

stdlib/public/BackDeployConcurrency/Actor.cpp

@@ -1228,7 +1228,7 @@ void DefaultActorImpl::giveUpThread(RunningJobInfo runner) {
     }
 
 #define LOG_STATE_TRANSITION                                                   \
-  SWIFT_TASK_DEBUG_LOG("actor %p transitioned from %zx to %zx (%s)\n", this,   \
+  SWIFT_TASK_DEBUG_LOG("actor %p transitioned from %zx to %zx (%s)", this,     \
                        oldState.Flags.getOpaqueValue(),                        \
                        newState.Flags.getOpaqueValue(), __FUNCTION__)
     LOG_STATE_TRANSITION;

stdlib/public/BackDeployConcurrency/TaskGroup.cpp

@@ -479,7 +479,7 @@ static void swift_taskGroup_initializeImpl(TaskGroup *group, const Metadata *T)
 // ==== add / attachChild ------------------------------------------------------
 
 void TaskGroup::addChildTask(AsyncTask *child) {
-  SWIFT_TASK_DEBUG_LOG("attach child task = %p to group = %p", child, group);
+  SWIFT_TASK_DEBUG_LOG("attach child task = %p to group = %p", child, this);
 
   // The counterpart of this (detachChild) is performed by the group itself,
   // when it offers the completed (child) task's value to a waiting task -

stdlib/public/BackDeployConcurrency/TaskPrivate.h

@@ -47,7 +47,7 @@ namespace swift {
 #if 0
 #define SWIFT_TASK_DEBUG_LOG(fmt, ...)                                         \
   fprintf(stderr, "[%lu] [%s:%d](%s) " fmt "\n",                               \
-          (unsigned long)Thread::current()::platformThreadId(),                \
+          (unsigned long)Thread::current().platformThreadId(),              \
           __FILE__, __LINE__, __FUNCTION__,                                    \
           __VA_ARGS__)
 #else

stdlib/toolchain/Compatibility56/include/Concurrency/TaskPrivate.h

@@ -29,7 +29,25 @@
 
 namespace swift {
 
+#if 0
+using ThreadID = decltype(pthread_self());
+
+inline ThreadID _swift_get_thread_id() {
+#if defined(_WIN32)
+  return GetCurrentThreadId();
+#else
+  return pthread_self();
+#endif
+}
+
+#define SWIFT_TASK_DEBUG_LOG(fmt, ...)                                         \
+  fprintf(stderr, "[%lu] [%s:%d](%s) " fmt "\n",                               \
+          (unsigned long)_swift_get_thread_id(),                               \
+          __FILE__, __LINE__, __FUNCTION__,                                    \
+          __VA_ARGS__)
+#else
 #define SWIFT_TASK_DEBUG_LOG(fmt ...) (void)0
+#endif
 
 /// Allocate task-local memory on behalf of a specific task,
 /// not necessarily the current one.  Generally this should only be