These tests started failing on the public build-bots recently
with following error:
```
AssertionError: 'error: Couldn't lookup symbols:
__ZNSt3__122__libcpp_verbose_abortEPKcz
' is not success
```
We've seen this previously when the SDKs we used to compile the
`std` module differ from the test program.
(see D146714, rdar://107052293, D139361, rdar://102427461)
Skip these tests on older MacOS versions for now.
This is possibly related to the recent `std` module changes in D144322.
rdar://113227172
Differential Revision: https://reviews.llvm.org/D156827
5ce7831b40