Fix and add comment explaining differences in typename test

Author: nycrat

src/software/util/typename/typename_test.cpp

@@ -17,7 +17,13 @@ class TestTypeA : public TestType
 TEST(TypeNameTest, abstract_base_class_concrete_subtype)
 {
     std::shared_ptr<TestType> test_type = std::make_shared<TestTypeA>();
+#ifdef __APPLE__
+    // With clang / libc++, the standard library uses an inline namespace '__1' for
+    // ABI versioning, which is reflected in the demangled type name.
+    EXPECT_EQ("std::__1::shared_ptr<TestType>", objectTypeName(test_type));
+#else
     EXPECT_EQ("std::shared_ptr<TestType>", objectTypeName(test_type));
+#endif
     EXPECT_EQ("TestTypeA", objectTypeName(*test_type));
 }