These two changes break macOS 10.12, which was previously working.
The descriptions suggest that these changes were tentative. In addition, the description for 5fa4e658 indicates that it's to fix #422 (closed) (compiler warnings on Solaris), but the only actual change is to make timex.h mandatory rather than optional, which doesn't seem like a warning fix (unless the intent is to completely break builds which previously only got warnings).
As things stand, builds on 10.12 (and earlier) fail configure. With 5fa4e658 reverted, configure works but build fails. With both reverted, those builds work again.