Stop relying on allocator behaviour in modules unit test

Another fixup for r355778 for Windows bots, this time to stop
accidentally relying on allocator behaviour for the test to pass.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@355780 91177308-0d34-0410-b5e6-96231b3b80d8

unittests/Serialization/InMemoryModuleCacheTest.cpp

@@ -71,12 +71,15 @@ TEST(InMemoryModuleCacheTest, addBuiltPCM) {
 }
 
 TEST(InMemoryModuleCacheTest, tryToDropPCM) {
-  auto B = getBuffer(1);
-  auto *RawB = B.get();
+  auto B1 = getBuffer(1);
+  auto B2 = getBuffer(2);
+  auto *RawB1 = B1.get();
+  auto *RawB2 = B2.get();
+  ASSERT_NE(RawB1, RawB2);
 
   InMemoryModuleCache Cache;
   EXPECT_EQ(InMemoryModuleCache::Unknown, Cache.getPCMState("B"));
-  EXPECT_EQ(RawB, &Cache.addPCM("B", std::move(B)));
+  EXPECT_EQ(RawB1, &Cache.addPCM("B", std::move(B1)));
   EXPECT_FALSE(Cache.tryToDropPCM("B"));
   EXPECT_EQ(nullptr, Cache.lookupPCM("B"));
   EXPECT_EQ(InMemoryModuleCache::ToBuild, Cache.getPCMState("B"));
@@ -90,17 +93,13 @@ TEST(InMemoryModuleCacheTest, tryToDropPCM) {
   EXPECT_DEATH(Cache.finalizePCM("B"), "Trying to finalize a dropped PCM");
 #endif
 
-  B = getBuffer(2);
-  ASSERT_NE(RawB, B.get());
-  RawB = B.get();
-
   // Add a new one.
-  EXPECT_EQ(RawB, &Cache.addBuiltPCM("B", std::move(B)));
+  EXPECT_EQ(RawB2, &Cache.addBuiltPCM("B", std::move(B2)));
   EXPECT_TRUE(Cache.isPCMFinal("B"));
 
   // Can try to drop again, but this should error and do nothing.
   EXPECT_TRUE(Cache.tryToDropPCM("B"));
-  EXPECT_EQ(RawB, Cache.lookupPCM("B"));
+  EXPECT_EQ(RawB2, Cache.lookupPCM("B"));
 }
 
 TEST(InMemoryModuleCacheTest, finalizePCM) {