This change should probably be made upstream as well, but they have a
note about not using it because it isn't available on all systems.
Change-Id: I6d8404c031bd2f486532ced55d94bbb4a4cd2e71
Well, kinda... localtime.c still contains a bunch of Android-specific
hacks, as does strftime.c. But the other files are now exactly the same
as upstream.
This catches up with several years of bug fixes, and fixes most of the
compiler warnings that were in this code. (Just two remain.)
Bug: 1744909
Change-Id: I2ddfecb6fd408c847397c17afb0fff859e27feef
