[Sanitizer][Apple] Enable sanitizer common unittests for arm64 archs on Apple

[thetruestblue]

Summary

This patch enables sanitizer common unit tests for arm64 architecture only on apple devices.

Also lowers the expected compression ratio for 64 bit machines. Unsure of justification of 130. On apple arm64 we're seeing this number comeout to 128.6

rdar://101436019

[rsundahl]

compiler-rt/lib/sanitizer_common/tests/sanitizer_stack_store_test.cpp

148

I think it'd be better to keep the test but reduce the 30% either for all targets or just for Apple arm64. I say this because it doesn't appear to be a test for the efficiency of the compression but rather that the compression is happening at all. (Nit: The comment is: "slightly than expected" but should be "slightly less than expected")

[thetruestblue]

Rather than skip the test, lower expected ratio. Per @rsundahl 's suggestion.

[MaskRay]

The use site is EXPECT_GE(kBlockSizeBytes / (kBlockSizeBytes - (before - after)), expected_ratio);

Lowering the number loosens the test but it should be fine.

[rsundahl]

LGTM. We can probably improve that ratio with some dictionary customization at some point. Thanks for the look @MaskRay.

compiler-rt/lib/sanitizer_common/tests/CMakeLists.txt

 include(CompilerRTCompile)
 
 clang_compiler_add_cxx_check()
 
 # FIXME: use SANITIZER_COMMON_SUPPORTED_ARCH here
 filter_available_targets(SANITIZER_UNITTEST_SUPPORTED_ARCH x86_64 i386 mips64 mips64el riscv64 sparcv9 sparc)
 if(APPLE)
+  list(APPEND SANITIZER_UNITTEST_SUPPORTED_ARCH arm64)
   darwin_filter_host_archs(SANITIZER_UNITTEST_SUPPORTED_ARCH SANITIZER_UNITTEST_SUPPORTED_ARCH)
 endif()
 
 set(SANITIZER_UNITTESTS
   sanitizer_addrhashmap_test.cpp
   sanitizer_allocator_test.cpp
   sanitizer_atomic_test.cpp
   sanitizer_bitvector_test.cpp

compiler-rt/lib/sanitizer_common/tests/sanitizer_stack_store_test.cpp

struct StackStorePackTest : public StackStoreTest,
                                 std::pair<StackStore::Compression, uptr>> {};
 
 INSTANTIATE_TEST_SUITE_P(
     PackUnpacks, StackStorePackTest,
     ::testing::ValuesIn({
         StackStorePackTest::ParamType(StackStore::Compression::Delta,
                                       FIRST_32_SECOND_64(2, 6)),
         StackStorePackTest::ParamType(StackStore::Compression::LZW,
-                                      FIRST_32_SECOND_64(60, 130)),
+                                      FIRST_32_SECOND_64(60, 125)),
     }));
 
 TEST_P(StackStorePackTest, PackUnpack) {
   std::vector<StackStore::Id> ids;
   StackStore::Compression type = GetParam().first;
   uptr expected_ratio = GetParam().second;
   ForEachTrace([&](const StackTrace& s) {
     uptr pack = 0;
     ids.push_back(store_.Store(s, &pack));
     if (pack) {
       uptr before = store_.Allocated();
       uptr diff = store_.Pack(type);
       uptr after = store_.Allocated();
       EXPECT_EQ(before - after, diff);
       EXPECT_LT(after, before);