Use __apple_build_version__ to detect Apple clang
#370
| Job | Run time |
|---|---|
| 1m 55s | |
| 26m 37s | |
| 3m 22s | |
| 2m 31s | |
| 27m 26s | |
| 6m 19s | |
| 3m 44s | |
| 28m 29s | |
| 5m 24s | |
| 23m 49s | |
| 2m 28s | |
| 5m 1s | |
| 2m 16s | |
| 24m 28s | |
| 2m 27s | |
| 4m 54s | |
| 2m 25s | |
| 2m 4s | |
| 1m 56s | |
| 2m 34s | |
| 3m 4s | |
| 3m 50s | |
| 2m 12s | |
| 2m 53s | |
| 2m 31s | |
| 2m 52s | |
| 3m 40s | |
| 3h 21m 11s |