Adds test.support.PGO and skips tests that are not useful for PGO.
diff --git a/Lib/test/libregrtest/main.py b/Lib/test/libregrtest/main.py
index ba9e48b..dbbf72f 100644
--- a/Lib/test/libregrtest/main.py
+++ b/Lib/test/libregrtest/main.py
@@ -473,6 +473,8 @@
         if self.ns.wait:
             input("Press any key to continue...")
 
+        support.PGO = self.ns.pgo
+
         setup_tests(self.ns)
 
         self.find_tests(tests)