[ADT] Move MoveOnly to a header file (NFC)

[kazu]

Summary

This patch moves MoveOnly to a header file so that I can use it from
another .cpp file.

[dblaikie]

Looks good - could you check if there are any other uses of something like this in other ADT tests that could share this implementation? (I would expect we have a few, maybe with the same name or something pretty similar)

llvm/unittests/ADT/CMakeLists.txt

add_llvm_unittest(ADTTests
   ImmutableSetTest.cpp
   IntEqClassesTest.cpp
   IntervalMapTest.cpp
   IntervalTreeTest.cpp
   IntrusiveRefCntPtrTest.cpp
   IteratorTest.cpp
   MappedIteratorTest.cpp
   MapVectorTest.cpp
+  MoveOnly.cpp
   OptionalTest.cpp
   PackedVectorTest.cpp
   PointerEmbeddedIntTest.cpp
   PointerIntPairTest.cpp
   PointerSumTypeTest.cpp
   PointerUnionTest.cpp
   PostOrderIteratorTest.cpp
   PriorityWorklistTest.cpp

llvm/unittests/ADT/MoveOnly.h

+//===- llvm/unittest/ADT/MoveOnly.h - Optional unit tests -----------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_UNITTESTS_ADT_MOVEONLY_H
+#define LLVM_UNITTESTS_ADT_MOVEONLY_H
+
+namespace llvm {
+
+struct MoveOnly {
+  static unsigned MoveConstructions;
+  static unsigned Destructions;
+  static unsigned MoveAssignments;
+  int val;
+  explicit MoveOnly(int val) : val(val) {
+  }
+  MoveOnly(MoveOnly&& other) {
+    val = other.val;
+    ++MoveConstructions;
+  }
+  MoveOnly &operator=(MoveOnly&& other) {
+    val = other.val;
+    ++MoveAssignments;
+    return *this;
+  }
+  ~MoveOnly() {
+    ++Destructions;
+  }
+  static void ResetCounts() {
+    MoveConstructions = 0;
+    Destructions = 0;
+    MoveAssignments = 0;
+  }
+};
+
+}  // end namespace llvm
+
+#endif // LLVM_UNITTESTS_ADT_MOVEONLY_H

llvm/unittests/ADT/MoveOnly.cpp

+//===- llvm/unittest/ADT/MoveOnly.cpp - Optional unit tests ---------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "MoveOnly.h"
+
+using namespace llvm;
+
+unsigned MoveOnly::MoveConstructions = 0;
+unsigned MoveOnly::Destructions = 0;
+unsigned MoveOnly::MoveAssignments = 0;

llvm/unittests/ADT/OptionalTest.cpp

 //===- llvm/unittest/ADT/OptionalTest.cpp - Optional unit tests -----------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/raw_ostream.h"
+#include "MoveOnly.h"
 #include "gtest/gtest-spi.h"
 #include "gtest/gtest.h"
 
 #include <array>
 #include <utility>
 
 using namespace llvm;
 
MultiArgConstructor::ResetCounts();
     Optional<MultiArgConstructor> B;
     B.emplace(1, 2);
     EXPECT_EQ(0u, MultiArgConstructor::Destructions);
     ASSERT_EQ(A, B);
   }
   EXPECT_EQ(2u, MultiArgConstructor::Destructions);
 }
 
-struct MoveOnly {
-  static unsigned MoveConstructions;
-  static unsigned Destructions;
-  static unsigned MoveAssignments;
-  int val;
-  explicit MoveOnly(int val) : val(val) {
-  }
-  MoveOnly(MoveOnly&& other) {
-    val = other.val;
-    ++MoveConstructions;
-  }
-  MoveOnly &operator=(MoveOnly&& other) {
-    val = other.val;
-    ++MoveAssignments;
-    return *this;
-  }
-  ~MoveOnly() {
-    ++Destructions;
-  }
-  static void ResetCounts() {
-    MoveConstructions = 0;
-    Destructions = 0;
-    MoveAssignments = 0;
-  }
-};
-
-unsigned MoveOnly::MoveConstructions = 0;
-unsigned MoveOnly::Destructions = 0;
-unsigned MoveOnly::MoveAssignments = 0;
-
 static_assert(!std::is_trivially_copyable_v<Optional<MoveOnly>>,
               "not trivially copyable");
 
 TEST(OptionalTest, MoveOnlyNull) {
   MoveOnly::ResetCounts();
   Optional<MoveOnly> O;
   EXPECT_EQ(0u, MoveOnly::MoveConstructions);
   EXPECT_EQ(0u, MoveOnly::MoveAssignments);