[compiler-rt] Fix intermittent failure with instrprof-gcov-multithread_fork.test on 32-bit arm

[rovka]

Summary

The test fails intermittently with 'terminate called recursively' errors likely
caused by having too many threads. This patch addresses the issue by
catching any exceptions thrown during thread creation.

[rovka]

@calixte: Does this affect the intention of the test in any way?

[calixte]

The base patch is not the correct one:
https://reviews.llvm.org/D81650
Oh I think I understand: the patch I made has been uplifted in branch 10 (https://bugs.llvm.org/show_bug.cgi?id=44792#c22) but no the test fix: https://reviews.llvm.org/D79621
So you must uplift patch in D79621 in branch 10 and if the issue is still there then add the try...catch like in D81650.
If it isn't clear enough then you can reach me on irc or discord.

[MaskRay]

Note, these files have nothing to do with instrprof, so they should be named gcov-*, rather than instrprof-gcov-*

compiler-rt/test/profile/Inputs/instrprof-gcov-multithread_fork.cpp

 #include <sys/types.h>
 #include <thread>
 #include <unistd.h>
 #include <vector>
 
 template <typename T>
 void launcher(T func) {
   std::vector<std::thread> pool;
-
-  for (int i = 0; i < 10; i++) {
-     pool.emplace_back(std::thread(func));
+
+  for (int i = 0; i < 10; i++) {
+    try {
+      pool.emplace_back(std::thread(func));
+    } catch (...) {
+    }
   }
 
   for (auto &t : pool) {
     t.join();
   }
 }
 
 void h() {}