[compiler-rt] [scudo] Added test fixture for cache tests. (PR #102230)

[Joshua Baehring via llvm-commits]

================
@@ -265,3 +265,99 @@ TEST_F(MapAllocatorWithReleaseTest, SecondaryThreadsRace) {
   Allocator->getStats(&Str);
   Str.output();
 }
+
+struct MapAllocatorCacheTest : public Test {
+  static constexpr scudo::u32 MarkerBytes = 0xDEADBEEF;
+
+  static void testUnmapCallback(scudo::MemMapT &MemMap) {
+    scudo::u32 *Ptr = reinterpret_cast<scudo::u32 *>(MemMap.getBase());
+    *Ptr = MarkerBytes;
+  }
+
+  using Config = scudo::DefaultConfig;
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JoshuaMBa wrote:

Do you mean use of `Config` directly?

I used `DefaultConfig` just because I assumed we would want to test it on the default values. There aren't any specific configuration requirements for this test fixture so if I set up a test config I wouldn't have any justification for using different values than the `DefaultConfig`.

https://github.com/llvm/llvm-project/pull/102230