[Test] Add regression test.

Author: nate-chandler

validation-test/SILOptimizer/issue-71495.swift

@@ -0,0 +1,48 @@
+// RUN: %target-run-simple-swift(-Xfrontend -sil-verify-all)
+// RUN: %target-run-simple-swift(-O -Xfrontend -sil-verify-all)
+
+// REQUIRES: executable_test
+
+/// A unique value represented by a heap memory location.
+struct Handle: ~Copyable {
+  var address: UnsafeMutableRawPointer
+
+  init() {
+    self.address = .allocate(byteCount: 2, alignment: 2)
+  }
+
+  consuming func done() {
+    let address = self.address
+    discard self
+    address.deallocate()
+    print("deallocated handle via done()")
+  }
+
+  deinit {
+    address.deallocate()
+    print("deallocated handle via deinit")
+  }
+}
+
+func description(of pointer: UnsafeRawPointer) -> String {
+  let address = UInt(bitPattern: pointer)
+  return "0x" + String(address, radix: 16)
+}
+
+func borrowHandleAndCrashNoMore(_ handle: borrowing Handle) -> String {
+  var string = ""
+  return string.withUTF8 { _ in
+    description(of: handle.address)
+  }
+}
+
+let handleDescription: String
+
+do {
+  let handle = Handle()
+  handleDescription = borrowHandleAndCrashNoMore(handle)
+  handle.done()
+}
+
+// CHECK: result: 0x
+print("result: \(handleDescription)")