- On macOS 10.15 and Xcode 11 -fstack-check is enabled by default. This
breaks SIMD alignment (and other alignment) as detailed here:
https://forums.developer.apple.com/thread/121887 resulting in random
segfaults from within Eigen.
- The underlying problem also exists with earlier OS versions running
Xcode 11 if -fstack-check is explicitly enabled.
- This CL explicitly disables -fstack-check on affected versions of
macOS 10.15 and Xcode 11.
Change-Id: I74d964281c360710d5fb722ac59e6930b0fdcc41
Alex Stewart