Add -O compile flag to test

Amanieu · Amanieu · commit 2af53e9a15ae · 2020-06-10T22:11:17.000+01:00
diff --git a/src/test/ui/tls.rs b/src/test/ui/tls.rs
@@ -1,4 +1,5 @@
 // run-pass
+// compile-flags: -O
 
 #![feature(thread_local)]
 
