[OpenMP] Fix releasing of stack memory

Starting with 787eb0c6 I got spurious segmentation faults for some testcases. I could nail it down to `brel` trying to release the "memory" of the node allocated on the stack of __kmpc_omp_wait_deps. With this patch, you will see the assertion triggering for some of the tests in the test suite.

My proposed solution for the issue is to just patch __kmpc_omp_wait_deps:
```
  __kmp_init_node(&node);
-  node.dn.on_stack = 1;
+  // the stack owns the node
+  __kmp_node_ref(&node);
```

What do you think?

Reviewed By: AndreyChurbanov

Differential Revision: https://reviews.llvm.org/D84472