[llvm] Attempt to fix: Sporadic Test Failure in thread.condition.condvarany/notify_one.pass.cpp (PR #106880)

[Arup Chauhan via llvm-commits]

https://github.com/Arup-Chauhan created https://github.com/llvm/llvm-project/pull/106880

Hello, I am creating this draft PR to address the sporadic test failure in `thread.condition.condvarany/notify_one.pass.cpp`
 within the LLVM `libcxx` test suite. The issue stems from timing assumptions that cause the test to fail intermittently in both internal and external CI environments.
 
 I had worked on MSVC's PR to unskip some of these sporadic tests prior.
 
Context: 

The proposed fix adapts the approach used in the `notify_all test` (Issue #95944 and PR #97622 ) to enhance reliability by ensuring synchronization without relying on specific timing. This change should reduce or eliminate the occurrence of sporadic failures in this test.

I was not able to find any issue raised for `notify_one.pass` issue similar to `notify_all.pass` issue, should I raise one to bind with this PR as well?

Please suggest @EugeneZelenko @lattner @topperc please suggest.

>From cabeb56c810f1c0c77c42b8991f173eab9542fe8 Mon Sep 17 00:00:00 2001
From: Arup Chauhan <arupchauhan26 at gmail.com>
Date: Sat, 31 Aug 2024 18:35:37 -0500
Subject: [PATCH] For fixing sporadic failure on notify_one.pass.cpp

Signed-off-by: Arup Chauhan <arupchauhan26 at gmail.com>
---
 draft_PR.txt | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 draft_PR.txt

diff --git a/draft_PR.txt b/draft_PR.txt
new file mode 100644
index 00000000000000..93f6c0ebedfea3
--- /dev/null
+++ b/draft_PR.txt
@@ -0,0 +1 @@
+Aim to fix sporadic failure of notify_one.pass.cpp
\ No newline at end of file