MFC r321342:
Pull in r295886 from upstream clang trunk (by Richard Smith):
PR32034: Evaluate _Atomic(T) in-place when T is a class or array type. This is necessary in order for the evaluation of an _Atomic initializer for those types to have an associated object, which an initializer for class or array type needs.
This fixes an assertion when building recent versions of LinuxCNC.
Reported by: trasz
PR: 220883