The Objective-C runtime now stashes some state in TLS (https://github.com/apple-oss-distributions/objc4/blob/689525d556eb3dee1ffb700423bccf5ecc501dbf/runtime/objc-initialize.mm#LL139C45-L139C45) so any test that indirectly initializes an Objective-C object will have false positive leaks unless use_tls=1 as is the default.
Example: https://bugs.chromium.org/p/chromium/issues/detail?id=1453649#c3
I removed use_tls=0 unconditionally because it doesn't seem essential to any of these tests. Happy to only do this for Darwin if that doesn't work :)