Correct and complete dependency sets after 74b411d3

Prior to this change the __support_cpp_array_ref target's only dependency was libc_root.
but it #includes "TypeTraits.h" and Array.h for that matter.

These dependencies matter when building in distributed build systems and the relevant
files must be know for the distributed build to ship them to the executor.

Differential Revision: https://reviews.llvm.org/D121974