[gardening] Add a test case for swiftlang#33984

I had this originally before landing swiftlang#33984, but it got merged while rebasing
into the wrong patch by mistake. Upstreaming ti now as a result.

Author: gottesmm

test/SILOptimizer/sil_stop_optzns_before_lowering_ownership_option.swift

@@ -0,0 +1,9 @@
+// Test that makes sure the pass pipeline respects the frontend option sil-stop-optzns-before-lowering-ownership
+//
+// RUN: %target-swift-frontend -sil-stop-optzns-before-lowering-ownership -Osize -emit-sil %s | %FileCheck %s
+// RUN: %target-swift-frontend -sil-stop-optzns-before-lowering-ownership -O -emit-sil %s | %FileCheck %s
+
+public class Klass {}
+
+// CHECK-LABEL: sil [ossa] @$s48sil_stop_optzns_before_lowering_ownership_option7theFuncAA5KlassCyF : $@convention(thin) () -> @owned Klass {
+public func theFunc() -> Klass { Klass() }