[TSan] Increase the number of simultaneously locked mutexes that a thread can hold

compiler-rt/lib/sanitizer_common/sanitizer_deadlock_detector.h

@@ -120,7 +120,7 @@ class DeadlockDetectorTLS {
     u32 lock;
     u32 stk;
   };
-  LockWithContext all_locks_with_contexts_[64];
+  LockWithContext all_locks_with_contexts_[128];
   uptr n_all_locks_;
 };
 

compiler-rt/test/tsan/many_held_mutex.cpp

@@ -0,0 +1,21 @@
+// RUN: %clangxx_tsan -O1 %s %link_libcxx_tsan -fsanitize=thread -o %t
+// RUN: %run %t 128
+
+#include <mutex>
+#include <vector>
+#include <string>
+
+int main(int argc, char *argv[]) {
+  int num_of_mtx = std::atoi(argv[1]);
+
+  std::vector<std::mutex> mutexes(num_of_mtx);
+
+  for (auto& mu : mutexes) {
+    mu.lock();
+  }
+  for (auto& mu : mutexes) {
+    mu.unlock();
+  }
+
+  return 0;
+}