run ClearRegisteredBenchmarks at exit (#1463)

bindings/python/google_benchmark/__init__.py

diff --git a/bindings/python/google_benchmark/__init__.py b/bindings/python/google_benchmark/__init__.py
index b249ca8..3dfabfb 100644
--- a/bindings/python/google_benchmark/__init__.py
+++ b/bindings/python/google_benchmark/__init__.py
@@ -26,6 +26,7 @@
   if __name__ == '__main__':
     benchmark.main()
 """
+import atexit
 
 from absl import app
 from google_benchmark import _benchmark
@@ -158,3 +159,4 @@
 # Methods for use with custom main function.
 initialize = _benchmark.Initialize
 run_benchmarks = _benchmark.RunSpecifiedBenchmarks
+atexit.register(_benchmark.ClearRegisteredBenchmarks)

bindings/python/google_benchmark/benchmark.cc

diff --git a/bindings/python/google_benchmark/benchmark.cc b/bindings/python/google_benchmark/benchmark.cc
index ea40990..5614b92 100644
--- a/bindings/python/google_benchmark/benchmark.cc
+++ b/bindings/python/google_benchmark/benchmark.cc
@@ -179,5 +179,6 @@
         py::return_value_policy::reference);
   m.def("RunSpecifiedBenchmarks",
         []() { benchmark::RunSpecifiedBenchmarks(); });
+  m.def("ClearRegisteredBenchmarks", benchmark::ClearRegisteredBenchmarks);
 };
 }  // namespace