swift

cab16250 - [6.0][Runtime] Use CMake variable to control os_trace_lazy_init usage.

[6.0][Runtime] Use CMake variable to control os_trace_lazy_init usage. SWIFT_BNI_OS_BUILD isn't exactly what we need. Use an option to turn it on/off instead. rdar://128408295 (cherry picked from commit 7f2d4be64254ae1bf5ddcab0d38c36357e29dcbd)