This attempts to address an issue with overload resolution for `PrintNumber`
with `size_t` parameters on Darwin, brought up in
https://reviews.llvm.org/D146492.
On Aarch64 Darwin, `uint64_t` has a different typedef than `size_t`
(e.g., `unsigned long long` vs. `unsigned long`), whereas on Linux and
Windows they are the same.
This commit also reverts the static_cast's added in
064e2497e2ebe9ac30ac96923a26a52484300fdf, since they are no longer
needed.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D146771