[test] Re-add crash tests for getObjects:andKeys:count:

On some platforms, when a new process is started, ARC’s autoreleased return value optimization is expected to fail the first time it is used in each linked dylib. StdlibUnittest takes care of warming up ARC for the stdlib (libswiftCore.dylib), but for Dictionary.swift, we also need to do it for Foundation, or there will be spurious leaks reported for tests immediately following a crash test.

Add the necessary dummy operations to setUp, and re-add the crash tests that were removed in #17862. (As separate tests this time, so they don’t hide leaks in non-crashing test parts.)

Author: lorentey

validation-test/stdlib/Dictionary.swift

@@ -3429,6 +3429,12 @@ DictionaryTestSuite.test("BridgedToObjC.Verbatim.getObjects:andKeys:count:") {
   }
 }
 
+DictionaryTestSuite.test("BridgedToObjC.Verbatim.getObjects:andKeys:count:/InvalidCount") {
+  expectCrashLater()
+  let d = getBridgedNSDictionaryOfRefTypesBridgedVerbatim()
+  checkGetObjectsAndKeys(d, count: -1)
+}
+
 //===---
 // Dictionary -> NSDictionary bridging tests.
 //
@@ -3534,6 +3540,12 @@ DictionaryTestSuite.test("BridgedToObjC.Custom.getObjects:andKeys:count:") {
   }
 }
 
+DictionaryTestSuite.test("BridgedToObjC.Custom.getObjects:andKeys:count:/InvalidCount") {
+  expectCrashLater()
+  let d = getBridgedNSDictionaryOfKeyValue_ValueTypesCustomBridged()
+  checkGetObjectsAndKeys(d, count: -1)
+}
+
 func getBridgedNSDictionaryOfKey_ValueTypeCustomBridged() -> NSDictionary {
   assert(!_isBridgedVerbatimToObjectiveC(TestBridgedKeyTy.self))
   assert(_isBridgedVerbatimToObjectiveC(TestObjCValueTy.self))
@@ -4749,6 +4761,22 @@ DictionaryTestSuite.test("Hashable") {
 }
 
 DictionaryTestSuite.setUp {
+#if _runtime(_ObjC)
+  // Exercise ARC's autoreleased return value optimization in Foundation.
+  //
+  // On some platforms, when a new process is started, the optimization is
+  // expected to fail the first time it is used in each linked
+  // dylib. StdlibUnittest takes care of warming up ARC for the stdlib
+  // (libswiftCore.dylib), but for this particular test we also need to do it
+  // for Foundation, or there will be spurious leaks reported for tests
+  // immediately following a crash test.
+  //
+  // <rdar://problem/42069800> stdlib tests: expectCrashLater() interferes with
+  // counting autoreleased live objects
+  let d = NSDictionary(objects: [1 as NSNumber], forKeys: [1 as NSNumber])
+  _ = d.object(forKey: 1 as NSNumber)
+#endif
+
   resetLeaksOfDictionaryKeysValues()
 #if _runtime(_ObjC)
   resetLeaksOfObjCDictionaryKeysValues()