[OpenMP] Clean up taskwait bug demonstration code

This patch removes the extra instrumentation to demonstrate the taskwait bug described in previous patches. All three patches can be committed together to reduce churn.

Author: jtb20

openmp/runtime/src/kmp.h

@@ -2556,9 +2556,6 @@ typedef struct kmp_base_depnode {
 #endif
  std::atomic<kmp_int32> npredecessors;
  std::atomic<kmp_int32> nrefs;
-#if KMP_DEBUG
- void *on_stack;
-#endif
 } kmp_base_depnode_t;
 
 union KMP_ALIGN_CACHE kmp_depnode {

openmp/runtime/src/kmp_taskdeps.cpp

@@ -48,9 +48,6 @@ static void __kmp_init_node(kmp_depnode_t *node) {
 #if USE_ITT_BUILD && USE_ITT_NOTIFY
  __itt_sync_create(node, "OMP task dep node", NULL, 0);
 #endif
-#if KMP_DEBUG
- node->dn.on_stack = NULL;
-#endif
 }
 
 static inline kmp_depnode_t *__kmp_node_ref(kmp_depnode_t *node) {

openmp/runtime/src/kmp_taskdeps.h

@@ -22,19 +22,12 @@ static inline void __kmp_node_deref(kmp_info_t *thread, kmp_depnode_t *node) {
  if (!node)
  return;
 
-#if KMP_DEBUG
- if (node->dn.on_stack && node->dn.on_stack != thread)
- fprintf (stderr, "on-stack depnode moved from thread %p to thread %p\n",
- node->dn.on_stack, thread);
-#endif
-
  kmp_int32 n = KMP_ATOMIC_DEC(&node->dn.nrefs) - 1;
  KMP_DEBUG_ASSERT(n >= 0);
  if (n == 0) {
 #if USE_ITT_BUILD && USE_ITT_NOTIFY
  __itt_sync_destroy(node);
 #endif
- KMP_DEBUG_ASSERT(!node->dn.on_stack);
  KMP_ASSERT(node->dn.nrefs == 0);
 #if USE_FAST_MEMORY
  __kmp_fast_free(thread, node);