Reducing stack usage of test

This test has a lot of classes with large amounts of manually inserted padding in them, presumably to prevent various optimizations. The test then creates lots of these objects on the stack. On embedded targets, this was usually enough to overflow the stack.

I moved the objects to global / namespace scope. Since the tests are each in their own namespace, there should be no cross-test conflicts.

git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@262717 91177308-0d34-0410-b5e6-96231b3b80d8