Lots of compiler warnings on macOS 10.12

[chdiza]

On macOS 10.12 building from master, I see a lot of compiler warnings. I have no idea whether these are important or whether they're related to the test failures I reported in #1415. The warnings I see are here: https://gist.github.com/chdiza/816921374243a6cc46a33c4b3b7a2112

[nicowilliams]

Can you post the config.log for your build?

[chdiza]

My config.log is here.

[nicowilliams]

@chdiza Thanks.

[nicowilliams]

@chdiza While I've not fixed all of these (and, indeed, some I won't), I've pushed b0d6d28 which might fix the warning about lgamma_r() -- can you confirm?

[chdiza]

@nicowilliams It did fix the lgamma_r warning, thanks.