qt: only disable SSSE3 on <=10.6.

Closes #22449.
debianutils 4.4

Closes #22450.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
libatomic_ops: 7.2d - portable atomic operations

Add a new formula for libatomic_ops that provides portable atomic
operations on many platforms.

Closes #21757.

Signed-off-by: Xiyue Deng <manphiz@gmail.com>
Fix CompilerSelector test for llvm

Update test to reflect that llvm-gcc should take precedence over
non-Apple GCC.
update: restore previous state when interrupted

Fixes #19460.
Closes #22375.