[Test] Add regression test.

For #68128 .

Author: nate-chandler

validation-test/SILOptimizer/issue-73859.swift

@@ -0,0 +1,37 @@
+// RUN: %target-run-simple-swift | %FileCheck %s
+
+// REQUIRES: executable_test
+
+class Object {
+    deinit { print("deinit object") }
+}
+
+struct Noncopyable: ~Copyable {
+    deinit { print("deinit noncopyable") }
+}
+
+func testDeinitAfterConsume() {
+    do {
+        let object = Object()
+        // CHECK: before consume
+        print("before consume")
+        // CHECK: deinit object
+        _ = consume object
+        // CHECK: after consume
+        print("after consume")
+    }
+    
+    print()
+    
+    do {
+        let noncopyable = Noncopyable()
+        // CHECK: before consume
+        print("before consume")
+        // CHECK: deinit noncopyable
+        _ = consume noncopyable
+        // CHECK: after consume
+        print("after consume")
+    }
+}
+
+testDeinitAfterConsume()