[llvm] [SystemZ][z/OS] z/OS does not support nanosleep, use usleep instead (PR #109823)

[Abhina Sree via llvm-commits]

https://github.com/abhina-sree created https://github.com/llvm/llvm-project/pull/109823

Use usleep instead of nanosleep to resolve a build error on z/OS because there is no support for nanosleep.

>From bc5b97cefdf598a1fc264df74f602c4dba2b393d Mon Sep 17 00:00:00 2001
From: Abhina Sreeskantharajan <Abhina.Sreeskantharajan at ibm.com>
Date: Tue, 24 Sep 2024 11:59:58 -0400
Subject: [PATCH] [SystemZ][z/OS] z/OS does not support nanosleep, use usleep
 instead

---
 llvm/unittests/Support/TimerTest.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/llvm/unittests/Support/TimerTest.cpp b/llvm/unittests/Support/TimerTest.cpp
index 09545eb6939aeb..30f9f132a8d15a 100644
--- a/llvm/unittests/Support/TimerTest.cpp
+++ b/llvm/unittests/Support/TimerTest.cpp
@@ -27,6 +27,10 @@ void SleepMS() {
   struct timespec Interval;
   Interval.tv_sec = 0;
   Interval.tv_nsec = 1000000;
+#if defined(__MVS__)
+  long Microseconds = (Interval.tv_nsec + 999) / 1000;
+  usleep(Microseconds);
+#else
   nanosleep(&Interval, nullptr);
 #endif
 }